//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25320 SUBJECT: LIGO/Virgo S190814bv: CLU/NED Galaxies in the 50% Localization Volume DATE: 19/08/14 21:57:10 GMT FROM: David Cook at IPAC/Caltech David O. Cook (Caltech/IPAC), Angela Van Sistine (UW Milwaukee), Leo Singer (NASA/GSFC), Igor Andreoni (Caltech), Michael Coughlin (Caltech), Bob Aloisi (UW Milwaukee), Patrick R. Brady (UW Milwaukee), Rick Ebert (Caltech/IPAC), George Helou (Caltech/IPAC), David Kaplan (UW Milwaukee), Mansi M. Kasliwal (Caltech), Joseph M. Mazzarella (Caltech/IPAC), and Marion Schmitz (Caltech/IPAC) On behalf of the Global Relay of Observatories Watching Transients Happen (GROWTH) collaboration and the NASA/IPAC Extragalactic Database (NED) Team. We spatially cross-matched the LIGO/Virgo S190814bv trigger sky localization (50% containment volume) with the Census of the Local Universe (CLU; Cook et al. 2017; arxiv:1710.05016) galaxy catalog and found 1185 galaxies within the volume. The CLU catalog is a compilation of galaxies with existing redshifts from many sources (e.g., NED, SDSS, etc) and new galaxies from a 3PI narrow-band survey to look for redshifted Halpha emission out to 200 Mpc with the Palomar Oschin 48-inch telescope (Cook et al. 2017; arxiv:1710.05016). We list here the top 20 galaxies sorted by stellar mass (Mstar) for galaxies whose location on the sky and distance falls in the 50% volume reported by the BAYESTAR probability sky map (Singer et al. 2016). We also list the dust-corrected star formation rates (SFRs) for galaxies with GALEX FUV detections and a 'nan' for those with no detection. For an extended list of galaxies in the 90% volume go to the NED Gravitational Wave Followup service at https://ned.ipac.caltech.edu/uri/NED::GWF/. This service provides downloadable galaxy lists and visualizations for candidate host galaxies. For each GW alert, these products are automatically generated and made available within minutes to expedite efficient electromagnetic followup observations. The NED top 20 list is sorted by 2MASS absolute K-band magnitude, but users can sort the entire list on a variety of other criteria (probability density, UV magnitudes, etc) after download. name ra dec distmpc logsfr_fuv logmstar dP_dV ---------------------------- -------- -------- ------- ---------- -------- -------- IC 0079 17.2071 -15.9486 182.00 -0.49 11.12 8.24e-07 MCG -06-52-004 356.7430 -35.7946 174.84 -0.68 11.07 6.64e-07 ESO 527-IG 007 301.1309 -26.4276 145.89 0.92 11.06 5.14e-07 2MASX J01402796-0446379 25.1165 -4.7773 174.00 0.65 11.05 6.08e-07 2MASX J20194224-2950376 304.9260 -29.8438 176.63 nan 11.04 6.78e-07 MCG -06-01-006 359.1155 -34.5934 197.34 nan 11.03 1.03e-06 ESO 408- G 037 357.4904 -35.4774 177.53 -0.27 11.01 7.12e-07 IC 0115 21.7268 19.2147 177.73 -0.52 11.00 5.84e-07 MCG -07-48-019 356.3465 -38.3366 178.46 nan 10.98 4.89e-07 CGCG 436-061 22.1799 12.3503 195.77 -0.57 10.98 6.10e-07 MCG -02-04-046 21.3175 -11.9140 193.00 -0.53 10.98 1.88e-06 MCG -01-04-038 21.2532 -4.6380 198.75 0.46 10.97 8.00e-07 6dF J0044160-283756 11.0665 -28.6323 179.64 1.08 10.97 8.16e-07 ESO 462- G 021 306.7886 -30.8197 178.14 nan 10.97 5.94e-07 2MASX J23474612-3729248 356.9423 -37.4903 182.35 0.84 10.96 6.83e-07 MCG -06-51-015 354.4543 -37.2264 183.00 nan 10.96 7.59e-07 2MASX J01105442-1857501 17.7268 -18.9639 196.00 -0.38 10.95 1.82e-06 MCG -06-52-007 357.5072 -35.6809 179.93 -0.47 10.93 7.68e-07 UGC 01163 24.4821 1.0014 185.00 -0.59 10.93 1.64e-06 CGCG 459-039 20.3991 18.3947 180.52 nan 10.93 4.83e-07 Table: Top 20 galaxies in CLU that fall in the 50% probability volume for S190814bv sorted by stellar mass. Column descriptions are as follows. name: galaxy name. ra: RA (J2000, decimal degrees). dec: Dec (J2000, decimal degrees). distmpc: galaxy distance (Mpc). logsfr_fuv: log10 of the star formation rate (SFR, Msun per year), derived from GALEX All Sky Kron FUV magnitudes via the prescription of Murphy et al. (2011), corrected for internal dust extinction using a combination of GALEX FUV and 22um ALLWISE fluxes (Hao et al. 2011). logmstar: log10 of the galaxy stellar mass (Msun), estimated from 3.4um ALLWISE fluxes and a mass-to-light ratio of 0.5 (McGaugh & Schombert et al. 2015). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25321 SUBJECT: LIGO/Virgo S190814bv: Upper limits from IceCube neutrino searches DATE: 19/08/14 22:06:41 GMT FROM: Raamis Hussain at IceCube IceCube Collaboration (http://icecube.wisc.edu/) reports: Searches [1,2] for track-like muon neutrino events detected by IceCube consistent with the sky localization of gravitational-wave candidate S190814bv in a time range of 1000 seconds [3] centered on the alert event time (2019-08-14 21:02:19.013 UTC to 2019-08-14 21:18:59.013 UTC) have been performed. During this time period IceCube was collecting good quality data. No significant track-like events are found in spatial coincidence of S190814bv calculated from the map circulated in the 2-Initial notice. IceCube's sensitivity assuming an E^-2 spectrum (E^2 dN/dE) to neutrino point sources within the locations spanned by the 90% spatial containment of S190814bv ranges from 0.029 to 0.639 GeV cm^-2 in a 1000 second time window. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc@icecube.wisc.edu [1] Bartos et al. arXiv:1810.11467 (2018) and Countryman et al.arXiv:1901.05486 (2019) [2] Braun et al., Astroparticle Physics 29, 299 (2008) [3] Baret et al., Astroparticle Physics 35, 1 (2011) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25322 SUBJECT: LIGO/Virgo S190814bv Global MASTER-Net observations report DATE: 19/08/14 22:28:29 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias) D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University) MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the LIGO/Virgo S190814bv errorbox 1327 sec after trigger time at 2019-08-14 21:32:46 UT, with upper limit up to 17.0 mag. The observations began at zenit distance = 78 deg. The sun altitude is -32.5 deg. MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) started inspect of the LIGO/Virgo S190814bv errorbox 1351 sec after trigger time at 2019-08-14 21:33:10 UT, with upper limit up to 19.4 mag. The observations began at zenit distance = 60 deg. The sun altitude is -66.1 deg. The galactic latitude b = -60 deg., longitude l = 98 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/ligo_1.php?id=10685 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 1417 | 2019-08-14 21:32:46 | MASTER-Kislovodsk | ( 0h 48m 40.64s , -23d 37m 08.26s) | C | 180 | 16.5 | 1417 | 2019-08-14 21:32:46 | MASTER-Kislovodsk | ( 0h 57m 30.97s , -24d 4m 38.55s) | C | 180 | 16.4 | 1442 | 2019-08-14 21:33:10 | MASTER-SAAO | ( 0h 58m 33.20s , -23d 51m 38.81s) | C | 180 | 18.6 | 1622 | 2019-08-14 21:33:10 | MASTER-SAAO | ( 0h 58m 33.20s , -23d 51m 38.79s) | C | 540 | 19.4 | Coadd 1622 | 2019-08-14 21:36:10 | MASTER-Kislovodsk | ( 0h 48m 41.16s , -23d 37m 12.34s) | C | 180 | 16.7 | 1622 | 2019-08-14 21:36:10 | MASTER-Kislovodsk | ( 0h 57m 31.42s , -24d 4m 42.24s) | C | 180 | 16.5 | 1826 | 2019-08-14 21:39:34 | MASTER-Kislovodsk | ( 0h 48m 41.48s , -23d 37m 09.80s) | C | 180 | 16.6 | 1826 | 2019-08-14 21:39:34 | MASTER-Kislovodsk | ( 0h 57m 31.77s , -24d 4m 38.97s) | C | 180 | 16.5 | 1941 | 2019-08-14 21:41:29 | MASTER-SAAO | ( 0h 58m 42.53s , -23d 51m 36.62s) | C | 180 | 18.4 | 2096 | 2019-08-14 21:44:04 | MASTER-Kislovodsk | ( 0h 48m 42.02s , -23d 37m 07.15s) | C | 180 | 16.9 | 2096 | 2019-08-14 21:44:04 | MASTER-Kislovodsk | ( 0h 57m 32.42s , -24d 4m 34.97s) | C | 180 | 17.0 | 2151 | 2019-08-14 21:44:59 | MASTER-SAAO | ( 0h 58m 49.53s , -23d 51m 26.28s) | C | 180 | 18.4 | 2300 | 2019-08-14 21:47:28 | MASTER-Kislovodsk | ( 0h 48m 42.27s , -23d 37m 03.87s) | C | 180 | 17.0 | 2300 | 2019-08-14 21:47:28 | MASTER-Kislovodsk | ( 0h 57m 32.81s , -24d 4m 29.98s) | C | 180 | 17.0 | 2365 | 2019-08-14 21:48:34 | MASTER-SAAO | ( 0h 58m 49.86s , -23d 51m 24.04s) | C | 180 | 18.6 | 2504 | 2019-08-14 21:50:53 | MASTER-Kislovodsk | ( 0h 48m 42.61s , -23d 37m 00.66s) | C | 180 | 16.9 | 2504 | 2019-08-14 21:50:53 | MASTER-Kislovodsk | ( 0h 57m 33.18s , -24d 4m 24.96s) | C | 180 | 17.0 | 2575 | 2019-08-14 21:52:03 | MASTER-SAAO | ( 0h 58m 50.07s , -23d 51m 23.28s) | C | 180 | 18.7 | 2709 | 2019-08-14 21:54:17 | MASTER-Kislovodsk | ( 0h 48m 42.74s , -23d 36m 57.59s) | C | 180 | 16.1 | 3481 | 2019-08-14 22:07:09 | MASTER-SAAO | ( 0h 32m 27.58s , -30d 3m 21.58s) | C | 180 | 18.5 | 3694 | 2019-08-14 22:10:43 | MASTER-SAAO | ( 0h 32m 28.11s , -30d 3m 37.65s) | C | 180 | 18.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25323 SUBJECT: LIGO/Virgo S190814bv: No counterpart candidates in INTEGRAL SPI-ACS prompt observation DATE: 19/08/14 22:29:45 GMT FROM: Sandro Mereghetti at IASF-Milano/INAF Sergey Molkov (IKI, Moscow, Russia), Sandro Mereghetti (INAF IASF-Milano, Italy), V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland), J. Rodi (IAPS-Roma, Italy), A. Coleiro (APC, France) on behalf of the INTEGRAL multi-messenger collaboration: https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration Using INTEGRAL/SPI-ACS realtime data (following [1]) we have performed a search for a prompt gamma-ray counterpart of S190814bv. At the time of the event (2019-08-14 21:10:39 UTC, hereafter T0), INTEGRAL was operating in nominal mode. The peak of the event localization probability was at an angle of 117 deg with respect to the spacecraft pointing axis. This orientation implies strongly suppressed (3.6% of optimal) response of ISGRI, somewhat suppressed (41% of optimal) response of IBIS/Veto, and somewhat suppressed (5 1% of optimal) response of SPI-ACS. The background within +/-300 seconds around the event was very stable (excess variance 1.2). We have performed a search for any impulsive events in INTEGRAL SPI- ACS (as described in [2]) data. We do not detect any significant counterparts and estimate a 3-sigma upper limit on the 75-2000 keV fluence of 3.1e-07 erg/cm^2 (within the 50% probability containement region of the source localization) for a burst lasting less than 1 s with a characteristic short GRB spectrum (an exponentially cut off power law with alpha=-0.5 and Ep=600 keV) occurring at any time in the interval within 300 s around T0. For a typical long GRB spectrum (Band function with alpha=-1, beta=-2.5, and Ep=300 keV), the derived peak flux upper limit is ~2.6e-07 (9.1e-08) erg/cm^2/s at 1 s (8 s) time scale in 75-2000 keV energy range. For the mean reported distance 236.0 Mpc this corresponds to the limit on the total isotropic equivalent energy in 1 s of 2.1e+48 erg for the short GRB spectrum and for a long GRB spectrum isotropic equivalent luminosity in 1 s (8 s) of 1.7e+48 erg/s (6.1e+47 erg/s) Overall, in the search region we identify 1 possibly associated excesses: scale | T | S/N | luminosity ( x 1e49 erg/s) | FAP 3.1 | 40.9 | 4 | 0.183 +/- 0.0432 +/- 0.0621 | 0.0413 5 likely background excesses: scale | T | S/N | luminosity ( x 1e49 erg/s) | FAP 0.45 | -10.7 | 3.5 | 0.398 +/- 0.114 +/- 0.135 | 0.163 2.5 | 63.9 | 3.1 | 0.155 +/- 0.0481 +/- 0.0525 | 0.443 1.25 | -34.1 | 3.1 | 0.221 +/- 0.0681 +/- 0.0749 | 0.504 0.3 | -42 | 3.8 | 0.523 +/- 0.14 +/- 0.178 | 0.591 0.25 | -53.4 | 4.1 | 0.616 +/- 0.153 +/- 0.209 | 0.616 Note that FAP estimates (especially at timescales above 2s) may be further affected possibly enhanced non-stationary local backgro und noise. This list excludes any excesses for which FAP is close to unity All results quoted are preliminary. This circular is an official product of the INTEGRAL Multi-Messenger team. [1] Savchenko et al. 2017, A&A 603, A46 [2] Savchenko et al. 2012, A&A 541A, 122S //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25324 SUBJECT: LIGO/Virgo S190814bv: Identification of a GW compact binary merger candidate DATE: 19/08/14 23:39:31 GMT FROM: Geoffrey Mo at LIGO The LIGO Scientific Collaboration and the Virgo Collaboration report: We identified the compact binary merger candidate S190814bv during real-time processing of data from LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) at 2019-08-14 21:10:39.013 UTC (GPS time: 1249852257.013). The candidate was found by the GstLAL [1], pycbc [2], MBTAOnline [3], and CWB [4] analysis pipelines. S190814bv is an event of interest because its false alarm rate, as estimated by the online analysis, is 2e-33 Hz, or about one in 1e25 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S190814bv The classification of the GW signal, in order of descending probability, is MassGap (>99%), Terrestrial (<1%), BNS (<1%), BBH (<1%), or NSBH (<1%). These values are based on point mass estimates which assigns an estimate of 100% to a single astrophysical class when the Terrestrial probability is very small. We will provide updates based on parameter estimation as soon as they become available. Assuming the candidate is astrophysical in origin, there is strong evidence against the lighter compact object having a mass < 3 solar masses (HasNS: <1%). Using the masses and spins inferred from the signal, there is strong evidence against matter outside the final compact object (HasRemnant: <1%). Two sky maps are available at this time and can be retrieved from the GraceDB event page: * a sky map generated by BAYESTAR [5] using data from the Livingston and Virgo detectors, distributed via GCN notice about 21 minutes after the candidate. * bayestar.fits.gz, an updated sky map generated by BAYESTAR using data from the Livingston, Hanford, and Virgo detectors, distributed about 2 hours after the candidate. This is the preferred skymap. The 90% credible region is 38 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 276 +/- 56 Mpc (a posteriori mean +/- standard deviation). For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo Public Alerts User Guide . [1] Messick et al. PRD 95, 042001 (2017) [2] Nitz et al. PRD 98, 024050 (2018) [3] Adams et al. CQG 33, 175012 (2016) [4] Klimenko et al. PRD 93, 042004 (2016) [5] Singer & Price PRD 93, 024013 (2016) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25325 SUBJECT: LIGO/Virgo S190814bv: Nordic Optical Telescope imaging of selected galaxies DATE: 19/08/15 03:52:38 GMT FROM: Daniele B Malesani at DTU Space Kasper E. Heintz (Univ. Iceland), Daniele B. Malesani (DTU Space), Jonatan Selsing (Novo Nordisk), Andrew J. Levan (Radboud Univ.), Paolo D'Avanzo (INAF/OABr), Daniel A. Perley (LJMU), Lana Salmon (UCD), Ana Sagues Carracedo (OKC Stockholm), Silvia Piranomonte (INAF/OAR),  A. Amanda Djupvik (NOT), Luca Malavolta (INAF/OACt), report on behalf of a larger collaboration: We observed the position of the 20 galaxies listed below, using the Nordic Optical Telescope equipped with the ALFOSC instrument. These argets were selected from the list of probable host galaxies generated by the HOGWARTS code (https://gwtool.watchertelescope.ie/), consistent with the 90% probability region of S190814bv (LIGO Scientific Collaboration and Virgo Collaboration, GCN 25324). Similar lists were coordinated with collaborating telescopes in La Palma: the Telescopio Nazionale Galileo, the Liverpool Telescope, and the William Hershel Telescope. Each galaxy was observed for 2 minutes exposure in the SDSS r filter. Observations started as soon as the targets were observable, around 2019 August 15.06 UT (4.3 hr after the GW event). Conditions were affected by the nearby bright Moon and large airmass. Visual inspection of the 20 fields does not reveal any new candidate compared with the deeper archival images from the Pan-STARRS survey. The typical limiting magnitude is r ~ 21 (3 sigma), though we caution that the actual limit is shallower at locations superimposed on the brightest parts of the targeted galaxies. This corresponds to an absolute magnitude M_r > -16.2 at a distance of 276 Mpc. List of target fields (RA, Dec) 00:47:07.527 -24:22:14.33 00:55:13.534 -26:19:16.51 00:50:54.447 -23:37:54.79 00:47:05.254 -24:14:19.33 00:55:09.151 -25:27:20.53 00:50:57.715 -23:33:28.78 00:50:09.705 -23:16:48.17 00:55:13.061 -24:02:38.52 00:48:58.272 -25:41:36.42 00:49:41.726 -25:03:02.93 00:48:24.757 -25:35:44.55 00:54:15.943 -23:32:06.58 00:44:13.189 -24:19:39.27 00:51:21.179 -26:59:22.02 00:46:13.218 -25:57:00.68 00:49:23.120 -26:30:26.99 00:50:12.393 -25:58:30.57 00:45:34.992 -24:14:54.74 00:47:52.584 -25:50:29.04 01:29:10.270 -31:34:41.63 [GCN OPS NOTE(15aug19): Per author's request, in the author list "Sagues-Corracedo" was changed to "Sagues Carracedo".] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25326 SUBJECT: LIGO/Virgo S190814bv: Upper limits from Fermi-GBM Observations DATE: 19/08/15 05:33:17 GMT FROM: Daniel Kocevski at GSFC D. Kocevski (NASA/MSFC) reports on behalf of the Fermi-GBM Team and the GBM-LIGO/Virgo group: For the LIGO/Virgo detection of GW trigger S190814bv (GCN 25324) and using the Updated BAYESTAR skymap, Fermi-GBM was observing 100% of the localization probability at event time. There was no Fermi-GBM onboard trigger immediately around the event time of S190814bv. The sky location of GRB 190814A (GCN 25319) that occurred ~1 hour before S190814bv is inconsistent with the updated skymap to high confidence. An automated, blind search for short gamma-ray bursts below the onboard triggering threshold in Fermi-GBM also identified no counterpart candidates. The GBM targeted search, the most sensitive, coherent search for GRB-like signals, was run from +/- 30 s around merger time, and also identified no counterpart candidates. We therefore set upper limits on impulsive gamma-ray emission. Using the representative soft, normal, and hard GRB-like templates described in arXiv:1612.02395, we set the following 3 sigma flux upper limits over 10-1000 keV (in units of 10^-8 erg/s/cm^2): Timescale soft norm hard -------------------------------------- 0.128 s: 17.0 31.0 58.0 1.024 s: 5.90 9.30 20.0 8.192 s: 2.20 3.10 5.68 Assuming the median luminosity distance of 276 Mpc (z=0.061) from the GW detection, we estimate the following intrinsic luminosity upper limits over the 1 keV-10 MeV energy range (in units of 10^48 erg/s): Timescale soft norm hard -------------------------------------- 0.128 s: 2.35 3.98 12.25 1.024 s: 0.81 1.19 4.23 8.192 s: 0.30 0.40 1.18 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25327 SUBJECT: LIGO/Virgo S190814bv: No counterpart candidates in AGILE-MCAL observations DATE: 19/08/15 06:46:03 GMT FROM: Maura Pillia at INAF M. Pilia (INAF/OA-Cagliari), C.Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), M. Cardillo, C. Casentini, G. Piano, A. Ursi (INAF/IAPS), F. Lucarelli, F. Verrecchia (SSDC, and INAF/OAR), A. Bulgarelli, V. Fioretti, N. Parmiggiani (INAF/OAS-Bologna), F. Longo (Univ. Trieste, and INFN Trieste) report on behalf of the AGILE Team: In response to the LIGO/Virgo GW event S190814bv at T0 = 2019-08-14 21:10:39 UTC, a preliminary analysis of the AGILE minicalorimeter (MCAL) triggered data found no event candidates within a time interval covering -/+ 15 sec from the LIGO/Virgo T0. At the T0, 100% of the S190814bv 90% c.l. localization region was accessible to the AGILE-MCAL. Three-sigma upper limits (ULs) are obtained for a 1 s integration time at different celestial positions within the accessible S190814bv localization region, from a minimum of 2.0E-06 erg cm^-2 to a maximum of 1.1E-06 erg cm^-2 (assuming as spectral model a single power law with photon index 1.5). The AGILE-MCAL detector is a CsI detector with a 4 pi FoV, sensitive in the energy range 0.4-100 MeV. Additional analysis of AGILE data is in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25328 SUBJECT: LIGO/Virgo S190814bv: Liverpool Telescope imaging of selected galaxies DATE: 19/08/15 07:17:36 GMT FROM: Daniel Perley at Liverpool JMU D. A. Perley, C. M. Copperwheat (LJMU), D. B. Malesani (DTU Space), and A. Levan (Radboud) report on behalf of the Global Relay of Observatories Watching Transients Happen (GROWTH) and other collaborations: We observed the locations of 19 galaxies within the error volume of S190814bf (LIGO Scientific Collaboration and Virgo Collaboration, GCN 25324), selected in coordination with other La Palma telescopes using the HOGWARTS code (https://gwtool.watchertelescope.ie/) as in GCN 25325 (Heintz et al.). Most galaxies were observed with 2x150 second exposures in r-band; several of the highest-probability candidates were also observed with 2x150 seconds in i-band. Observations took place between 01:38 and 05:33 UT. Visual inspection shows no apparent candidates in any of the images in comparison to archival imaging from Pan-STARRS. Target locations were: RA Dec Filters ----------- ------------ ------- 00:47:07.53 -24:22:14.33 (r+i) 00:48:43.29 -23:33:42.07 (r+i) 00:49:01.48 -23:48:40.74 (r+i) 00:48:21.86 -25:07:36.53 (r+i) 00:51:29.86 -24:38:32.98 (r+i) 00:52:41.58 -25:44:01.87 (r) 00:45:53.29 -23:46:20.86 (r+i) 00:46:10.42 -24:39:00.69 (r) 00:49:16.82 -26:13:09.04 (r) 00:48:42.78 -23:46:23.07 (r) 00:42:42.31 -21:46:26.70 (r) 00:50:33.09 -23:17:43.76 (r) 00:49:46.03 -26:26:34.93 (r) 00:53:04.63 -24:42:15.84 (r) 00:44:50.54 -23:09:32.50 (r) 00:40:58.26 -22:04:59.26 (r) 00:45:46.31 -25:55:12.69 (r) 00:50:52.42 -25:34:37.42 (r) 00:46:52.96 -23:02:00.17 (r) ________________________________ Important Notice: the information in this email and any attachments is for the sole use of the intended recipient(s). If you are not an intended recipient, or a person responsible for delivering it to an intended recipient, you should delete it from your system immediately without disclosing its contents elsewhere and advise the sender by returning the email or by telephoning a number contained in the body of the email. No responsibility is accepted for loss or damage arising from viruses or changes made to this message after it was sent. The views contained in this email are those of the author and not necessarily those of Liverpool John Moores University. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25329 SUBJECT: LIGO/Virgo S190814bv: Coverage and upper limits from MAXI/GSC observations DATE: 19/08/15 07:34:39 GMT FROM: Mutsumi Sugizaki at Tokyo Tech./MAXI M. Sugizaki, N. Kawai (Tokyo Tech), H. Negoro (Nihon U.), S. Sugita, M. Serino (AGU), M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi (Nihon U.), T. Mihara, T. Tamagawa, M. Matsuoka (RIKEN), T. Sakamoto, H. Nishida, A. Yoshida (AGU), Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, T. Sato (Chuo U.), M. Shidatsu (Ehime U.), M. Oeda, K. Shiraishi (Tokyo Tech), S. Nakahira, Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, N. Isobe, R. Shimomukai, M. Tominaga (JAXA), Y. Ueda, A. Tanimoto, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake (Kyoto U.), H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.), M. Yamauchi, S. Iwahori, Y. Kurihara, K. Kurogi, K. Miike (Miyazaki U.), T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU) report on behalf of the MAXI team: We examined MAXI/GSC all-sky X-ray images (2-20 keV) after the LVC trigger S190814bv at 2019-08-14 21:10:39.013 UTC (GCN #25324). At the trigger time of S190814bv, the high-voltage of MAXI/GSC was off, and it was turned on at T0+616 sec (+10.3 min). The first scan observation with GSC after the event covered 100% of the 90% credible region of the bayestar skymap from 02:17:32 to 02:19:27 UTC (T0+18413 to T0+18528 sec). The first GSC scan covering the whole 90% credible region of the bayestar skymap was made from 02:17:32 to 02:19:27 UTC (T0+18413 to T0+18528 sec). No significant new source was found in the region in the one-orbit scan observation. A typical 1-sigma averaged upper limit obtained in one scan observation is 20 mCrab at 2-20 keV. If you require information about X-ray flux by MAXI/GSC at specific coordinates, please contact the submitter of this circular by email. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25330 SUBJECT: LIGO/Virgo S190814bv : no neutrino counterpart candidate in ANTARES search DATE: 19/08/15 08:21:11 GMT FROM: Antoine Kouchner at ANTARES Collaboration M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (APC/Universite de Paris), M. Colomer (APC/Universite de Paris), D. Dornic (CPPM/CNRS), A. Kouchner (APC/Universite de Paris), T. Pradier (IPHC/Universite de Strasbourg) report on behalf of the ANTARES Collaboration: Using on-line data from the ANTARES detector, we have performed a follow-up analysis of the recently reported LIGO/Virgo S190814bv event using the 90% contour of the updated bayestar probability map provided by the GW interferometers about two hours after the candidate (GCN#25324 ). The ANTARES visibility at the time of the alert, together with the 50% and 90% contours of the probability map are shown at http://antares.in2p3.fr/GW/S190814bv.png . Considering the location probability provided by the LIGO/Virgo collaborations, there is a 99.9% chance that the GW emitter was in the ANTARES **upgoing** field of view at the time of the alert. No up-going muon neutrino candidate events were recorded in the ANTARES sky during a +/-500s time-window centered on the time 2019-08-14 21:10:39 and in the 90% contour of the S190814bv event. The expected number of atmospheric background events in the region visible by ANTARES is 4.04e-05 in the +/- 500s time window. An extended search during +/- 1 hour gives no up-going muon neutrino coincidence. The expected number of atmospheric background events in the region visible by ANTARES is 2.91e-04 in this larger time window. ANTARES is the largest undersea neutrino detector, installed in the Mediterranean Sea, and it is primarily sensitive to neutrinos in the TeV-PeV energy range. At 10 TeV, the median angular resolution for muon neutrinos is about 0.5 degrees. In the range 1-100 TeV ANTARES has a competitive sensitivity to this position in the sky. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25331 SUBJECT: LIGO/Virgo S190814bv: GRAWITA TNG imaging of selected galaxies DATE: 19/08/15 08:55:59 GMT FROM: Paolo D'Avanzo at INAF-OAB LIGO/Virgo S190814bv: GRAWITA TNG imaging of selected galaxies P. D'Avanzo, A. Melandri (INAF-OAB), L. Izzo (IAA/CSIC), M. Branchesi (GSSI), V. D'Elia (ASI-SSDC), G. Greco (Urbino Univ.), S. Piranomonte (INAF-OAR), A. Rossi (INAF-OAS), V. Testa (INAF-OAR), W. Boschin, A. Bragaglia, D. Carosati (INAF-TNG), A. J. Levan (Radboud Univ.), D. B. Malesani (DTU Space), D. A. Perley (LJMU), Lana Salmon (UCD) on behalf of GRAWITA and other collaborations report: We observed the position of the 10 galaxies listed below, with the 3.6m Italian TNG telescope (Canary Islands, Spain), equipped with the DOLORES camera in imaging mode. These targets were selected from the list of probable host galaxies generated by the HOGWARTS code (https://gwtool.watchertelescope.ie/), consistent with the 90% probability region of S190814bv (LIGO Scientific Collaboration and Virgo Collaboration, GCN Circ. 25324). Similar lists were coordinated with collaborating telescopes in La Palma as in Heintz et al. (GCN Circ. 25324) and Perley et al. (GCN Circ. 25328). Each galaxy was observed for 2 minutes exposure in the SDSS r filter. Observations were carried out on 2019 Aug 15 between 02:13 and 02:54 UT. Conditions were affected by the nearby bright Moon and large airmass. Visual inspection of the 10 fields does not reveal any new candidate compared with archival images from the Pan-STARRS survey. List of target fields (RA, Dec): ------------------------------- 00:48:43.29 -23:33:42.07 00:47:28.95 -25:26:26.36 00:45:53.29 -23:46:20.86 00:53:57.74 -24:32:35.31 00:52:46.17 -22:58:30.06 00:50:34.51 -23:37:06.77 00:51:18.76 -26:10:05.02 00:49:27.55 -26:32:17.88 00:48:54.95 -25:04:10.09 00:50:33.41 -23:00:59.77 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25332 SUBJECT: LIGO/Virgo S190814bv: no candidates from WHT imaging of candidate galaxies DATE: 19/08/15 09:58:43 GMT FROM: Andrew Levan at U.of Leicester A.J. Levan (Radboud Univ), M. Fraser (UCD), P. Jonker (SRON/Radboud Univ), D. Steeghs (Warwick), D.B. Malesani (DTU Space), L. Salmon, K. Maguire (UCD), D. Perley, C. Copperwheat (LJMU), P. D’Avanzo (INAF) report for a larger collaboration: We observed 17 galaxies within the 90% error volume of S190814bv (LVC GCN 25324) with the William Herschel Telescope, in co-ordination with several other telescopes on La Palma (Heintz et al. GCN 25325, Perley et al. GCN 25328, D’Avanzo et al. GCN 25331). Observations were obtained on 15 August 2019 between 03:28 and 04:49 UT. Galaxies were selected from the HOGWARTS code (https://gwtool.watchertelescope.ie/)). For each galaxy we obtained 3x60s r-band observations in good seeing. Comparison with archival Pan-STARRS imaging reveals no obvious counterparts in any cases to similar limiting magnitudes to the Pan-STARRS images, although we caution that fainter candidates close to their hosts could be omitted in such an inspection. The locations of the galaxies observed are RA(J2000) DEC (J2000) 0h49m01.48s -23d48m40.7s 0h51m29.86s -24d38m32.9s 0h54m49.13s -26d22m16.5s 0h48m41.98s -23d22m07.0s 0h54m37.67s -25d04m01.5s 0h49m53.54s -24d42m25.9s 0h51m10.52s -25d57m15.0s 0h52m15.36s -24d41m55.4s 0h50m39.87s -26d48m48.2s 0h42m33.38s -22d51m58.7s 0h53m04.27s -26d10m14.8s 0h51m12.21s -26d18m47.0s 0h57m01.11s -23d50m14.2s 0h51m15.64s -23d17m39.8s 0h43m33.26s -23d57m10.4s 0h50m43.18s -22d53m17.7s 0h44m48.49s -22d06m59.5s We thanks the staff of ING and in particular Ovidiu Vaduvescu for their help in acquiring these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25333 SUBJECT: LIGO/Virgo S190814bv: Update on Sky-Localization and Source-Classification DATE: 19/08/15 10:41:01 GMT FROM: Geoffrey Mo at LIGO The LIGO Scientific Collaboration and Virgo Collaboration report: We have conducted further analysis of the LIGO and Virgo data around the time of the compact binary coalescence (CBC) candidate S190814bv (GCN 25324). Parameter estimation has been performed using LALInference [1] and a new sky map, LALInference.v1.fits.gz, distributed via GCN Notice, is available for retrieval from the GraceDB event page: https://gracedb.ligo.org/superevents/S190814bv/ LALInference.v1.fits.gz is the preferred sky map at this time. The 90% credible region is 23 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 267 +/- 52 Mpc (a posteriori mean +/- standard deviation). Based on posterior support from parameter estimation [1, 2], under the assumption that the candidate S190814bv is astrophysical in origin, there is strong evidence that the lighter compact object has a mass < 3 solar masses (HasNS > 99%) and a negligible probability of having disrupted material outside the final compact object (HasRemnant < 1%). The parameter estimation based classification of the GW signal, in order of descending probability, is NSBH (>99%), MassGap (<1%), BBH (<1%), or BNS (<1%). The above mentioned probabilities are the preferred classification results that supersede the ones stated in GCN 25324. The probability of non-astrophysical origin and the false alarm rate are not being updated at this time. For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo Public Alerts User Guide . [1] Veitch, et al. PRD 91, 042003 (2015) [2] Abbott, et al. PRL 116, 241102 (2016) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25335 SUBJECT: LIGO/Virgo S190814bv: Upper limits from AGILE-GRID observations DATE: 19/08/15 11:36:07 GMT FROM: Maura Pillia at INAF M. Pilia (INAF/OA-Cagliari), C.Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), F. Lucarelli, F. Verrecchia (SSDC, and INAF/OAR), F. Longo (Univ. Trieste, and INFN Trieste), M. Cardillo, C. Casentini, G. Piano, A. Ursi (INAF/IAPS), A. Bulgarelli, V. Fioretti, N. Parmiggiani (INAF/OAS-Bologna), report on behalf of the AGILE Team: In response to the LIGO-Virgo GW event S190814bv at T0 = 2019-08-14 21:10:39(UT), a preliminary analysis of the AGILE data at T0 shows that the Gamma-Ray Imaging Detector (GRID) exposure covered ~100% of the 90% c.l. localization region (LR), observed at off-axis angles above 60 deg. We performed an analysis of the GRID data in the energy range 50 MeV - 10 GeV on T0, when good exposure of the S190814bv 90% c.l. LR was available. No candidate gamma-ray transient was detected. The following preliminary GRID values of 3-sigma upper limit (UL) are obtained: (T0-2s; T0+2s): from 2.1e-06 to 4.0e-06 erg cm^-2 s^-1; (T0; T0+5s): from 2.0e-06 to 5.2e-06 erg cm^-2 s^-1; (T0; T0+10s); from 1.1e-06 to 5.2e-06 erg cm^-2 s^-1; (T0; T0+100s); from 5.7e-07 to 5.2e-06 erg cm^-2 s^-1. These measurements were obtained with AGILE observing a large portion of the sky in spinning mode. Additional analysis of AGILE data is in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25336 SUBJECT: LIGO/Virgo S190814bv: Candidates found in initial DESGW search DATE: 19/08/15 11:39:15 GMT FROM: M. Soares-Santos at Fermi Lab Marcelle Soares-Santos, Douglas Tucker, Sahar Allam, James Annis, Alyssa Garcia, Ken Herner, Tamara Davis, Nora Sherman, Robert Morgan, Kathy Vivas, Chris Lidman, Umang Malik On behalf of the DESGW team*: We report initial results of our DECam search for an optical counterpart of S190814bv (LVC, GCN 25324) using DECam. Starting at 2019-08-15 06:32 UTC (9.5h post merger), we observed 54 sq-deg, covering the 90% localization region provided in the updated sky map released on Aug 14, 2019 22:58:20 UTC. Observations were performed through clouds which limited the depth of our observations to 20.2 mag (10-sigma point source). Images were processed by our difference imaging pipeline (Herner et al. 2017; see also Soares-Santos et al. 2015, 2017; Doctor et al. 2018; Morgan et al. 2019 for recent applications) using DES images as templates. We employ a machine learning code (autoscan, Goldstein et al. 2015) to reject subtraction artifacts. Candidates were initially selected by requiring at least two high signal to noise detections, rejecting asteroids. We then applied catalog-based vetting to reject variable stars, variable AGNs, and candidates with hosts at redshifts inconsistent with the distance reported by the LVC for S190814bv (276 +/- 56 Mpc). Those catalogs included Gaia DR2, and DES. The final vetting was done via visual inspection. We matched our remaining candidates using the Transient Name Server to avoid reporting those previously reported by other groups. In our initial analysis, we find 2 new transient candidates: one hostless and one with a host at marginally consistent redshift: NAME TNS_NAME RA DEC DISCOVERY_MJD DISCOVERY_MAG_I DISCOVERY_MAG_Z desgw-190814a 2019nmd 12.870848 -22.471377 58710.278 20.59 20.26 desgw-190814b 2019nme 12.635660 -22.226027 58710.278 19.33 19.39 CANDIDATE_ID HOST_ID HOST_MAG HOST_Z HOST_ZERR ANG_SEP desgw-190814b 2MASS J00503145-2213363 20.3 0.23 0.20 14’’ All magnitudes reported are observed magnitudes. We encourage spectroscopic followup of these candidates. We detected also a transient previously reported by ZTF: AT2019mbq Since the start of our observations, S190814bv has been reclassified as a NSBH. We notice that if such a source caused a GW170817-like kilonova it would peak at magnitude 21.6 at this distance. Such a source would not be detectable in our data. The DECam Search & Discovery Program for Optical Signatures of Gravitational Wave Events (DESGW) is carried out by the Dark Energy Survey (DES) collaboration in partnership with wide ranging groups in the community. DESGW uses data obtained with the Dark Energy Camera (DECam), which was constructed by the DES collaboration with support from the Department of Energy and member institutions, and utilizes data as distributed by the Science Data Archive at NOAO. NOAO is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. *DESGW collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner, (Fermilab), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Chris Lidman (ANU), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25337 SUBJECT: LIGO/Virgo S190814bv: no candidates from GOTO imaging observations DATE: 19/08/15 12:03:12 GMT FROM: Rhaana Starling at U of Leicester K. Ackley(2), M.Dyer(3), R.Eyles(4), D.K.Galloway(2), B.Gompertz(1), M.Kennedy(8), A.J.Levan(1), J.Lyman(1), Y-L.Mong(2), A.Obradovic(2), G.Ramsay(5), D.Steeghs(1), E.Stanway(1), R.Starling(4), K.Wiersema(1), K.Ulaczyk(1), L.Makrygianni(3), V.Dhillon(3), P.O'Brien(4), D.Pollacco(1), E.Thrane(2), S.Poshyachinda(6), E.Palle(7), R.Cutter(1), T. Marsh(1), R.West(1), A.Casey(2), M.Brown(2), E.Rol(2), J.Mullaney(3), S.Littlefair(3), E.Daw(3), J.Maund(3), S.Tooke(4), U.Sawangwit(6), D.Mkrtichian(6), S.Awiphan(6), S.Aukkaravittayapun(6), P.Irawati(6), R.Breton(8), D.Mata-Sanchez(8), T.Heikkila(9), R.Kotak(9), L.Nuttall (10) (1) Warwick University; (2) Monash University; (3) Univ. of Sheffield; (4) Univ. of Leicester; (5) Armagh Observatory & Planetarium; (6) National Astronomical Research Institute of Thailand; (7) Instituto de Astrofisica de Canarias; (8) Univ. of Manchester; (9) University of Turku; (10) Univ. of Portsmouth report on behalf of the GOTO collaboration: We carried out observations with the Gravitational-wave Optical Transient Observer (GOTO) on La Palma, in response to the LIGO/Virgo gravitational wave event S190814bv triggered 2019 Aug 14 at 21:10:39 UT. We made a series of 6 x 90 s exposures using our wide L-band filter (400-700 nm) covering ~89% of the estimated sky probability region. Observations started on 2019 Aug 15 00:39 UT (3.5 hrs post-burst) and ended 2019 Aug 15 05:36 UT. Using a difference imaging analysis with recent survey observations of the same pointings as reference, we identify no viable counterparts at this time. Our mean 5-sigma detection limit was g~18.4 mag based on PS1 catalogue calibrators, and reached g=18.9 in the deepest images (the event took place near full moon). GOTO is operated at the La Palma observing facilities of the University of Warwick on behalf of a consortium including the University of Warwick, Monash University, Armagh Observatory, the University of Leicester, the University of Sheffield, the National Astronomical Research Institute of Thailand (NARIT) and the Instituto de Astrofisica de Canarias (IAC) (https://goto-observatory.org) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25338 SUBJECT: LIGO/Virgo S190814bv : No counterpart candidate in TAROT-GRANDMA observations DATE: 19/08/15 13:27:35 GMT FROM: Nicolas Leroy at LAL A. Klotz (IRAP), V. Aivazyan (Iliauni), X. Zhang (THU), R. Natsvlishvili (Iliauni), M. Boer (Artemis), N. Christensen (Artemis), L. Eymar (Artemis), K. Noysena (Artemis, IRAP), S. Antier (APC), S. Basa (LAM), D. Corre (LAL), D. Coward (OzGrav-UWA), J.G. Ducoin (LAL), B. Gendre (OzGrav-UWA), P. Hello (LAL), C. Lachaud (APC), N. Leroy (LAL), D. Turpin (NAOC) Report on behalf of the TAROT network and GRANDMA collaborations. We performed tiled observations of LIGO/Virgo S190814bv event with the  TAROT-Calern (TCA) telescope operating in the visible located at Calern site at the Cote d'Azur observatory. The observation started on 08/15/19 00:09:41 UTC which corresponds approximately to 180 minutes after the GW trigger time. We performed the following tiled observations : +------------+------------+---------+---------+---------+ | TStart     | TEnd       | RA      | DEC     |   Proba | | [UTC]      | [UTC]      | [deg]   | [deg]   |     [%] | |------------+------------+---------+---------+---------| | 2019-08-15 | 2019-08-15 | 14.078  | -23.196 |     5   | | 00:09:41   | 02:24:40   |         |         |         | | 2019-08-15 | 2019-08-15 | 9.945   | -21.34  |     1.3 | | 00:29:08   | 01:05:38   |         |         |         | | 2019-08-15 | 2019-08-15 | 10.056  | -23.196 |     3.5 | | 00:49:07   | 02:29:14   |         |         |         | | 2019-08-15 | 2019-08-15 | 12.067  | -23.196 |    16   | | 02:11:19   | 02:17:49   |         |         |         | | 2019-08-15 | 2019-08-15 | 11.934  | -21.34  |     1.7 | | 02:31:49   | 02:38:20   |         |         |         | +------------+------------+---------+---------+---------+ TStart and TEnd refers respectively to the time of the first and last exposure for a given tile. Observations are not necessarily continuous  in this interval. The Probability refers to the 2D spatial probability of the GW skymap enclosed in a given tile. Each tile is 1.9x1.9 degrees. These observations cover about 27% of the cumulative probability of the bayestar skymap with HLV. The typical limiting magnitude is 18.0 for a 60.0 s exposure. The coverage map is available at: https://grandma-owncloud.lal.in2p3.fr/index.php/s/7Y1Zos9G2n0rrrs No serious transient candidates were found during our low latency analysis. GRANDMA (Global Rapid Advanced Network Devoted to the Multi-messenger Addicts) is a network of robotic telescopes connected all over the world with both photometry and spectrometry capabilities for Time- domain Astronomy (https://grandma.lal.in2p3.fr/). Details on the TCA telescope  are available on the GRANDMA web pages or on  http://tarot.obs-hp.fr/. This circular is citable. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25339 SUBJECT: LIGO/Virgo S190814bv Global MASTER-Net optical observations DATE: 19/08/15 13:57:46 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, D.Vlasenko, P.Balanutsa, D.Vlasenko, V.Vladimirov, D.Zimnukhov, A.Kuznetsov, P.Balanutsa,I.Gorbunov, A. Chasovnikov, F.Balakin, V.Grinshpun, T.Pogrosheva, A.Poznyakov (Lomonosov Moscow State University, SAI, Physics Department), R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov (Kislovodsk Solar Station ofthe Pulkovo Observatory), R. Podesta, C. Lopez, C.Francile, F. Podesta (Observatorio Astronomico Felix Aguilar OAFA, San Juan National University), H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE,SJNU) O. Gress, N.M. Budnev, O.Ershova (Applied Physics Institute, Irkutsk Stat University), V. Yurkov, A. Gabovich, Yu. Sergienko, D. Kobcev (Blagoveschensk Education State University) MASTER-Kislovodsk, MASTER-IAC and MASTER-OAFA robotic telescopes (Lipunov et al. GCN 25322) made a series of 9 images of DESGW OTs area (2019nmd and 2019nme, M.Soares-Santos et al GCN 25336) during last night since 2019-08-14 22:42:29 till 2019-08-15 05:43:57. We do not see any OT at this position up to 18 mag this night (Error-box-Altitude: 18deg; Sun_Alt: -47.2 deg., Moon_Alt:43.35 deg., Distane to Moon: 49 deg), and on 2018-11-03 00:13:30UT with m_lim=21. Full Moon and cirrus made heterogeneous limits on different inspect images. The list of times when we cover OTs area. 2019-08-15 05:43:57 2019-08-15 05:32:34 2019-08-15 03:42:43 2019-08-15 03:27:38 2019-08-15 00:56:36 2019-08-15 00:55:33 2019-08-15 00:42:49 2019-08-14 22:53:24 2019-08-14 22:42:29 During LVC S190814bv (LVC GCN 25324) error-box inspect (Lipunov et al. GCN 25322), MASTER-IAC auto-detection system found MASTER OT J003814.71-245902.0 - QSO flare at (RA, Dec) = 00h 38m 14.71s -24d 59m 02.0s on 2019-08-15.20078 UT. The OT unfiltered magnitude is 15.3m (limit 18.6m). We have reference images on 2015-09-14.09730 UT with m_OT=19.2 and unfiltered magnitude limit 21.0m. The observation and reduction will be continued. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25340 SUBJECT: LIGO/Virgo S190814bv: MeerLICHT coverage second preliminary skymap DATE: 19/08/15 14:06:00 GMT FROM: Paul Vreeswijk at Radboud U/Nijmegen Paul Groot (Radboud/UCT/SAAO), Paul Vreeswijk (Radboud), Steven Bloemen (Radboud), Danielle Pieterse (Radboud), Lee Townsend (UCT), Rudolf Le Poole (Leiden), Patrick Woudt (UCT), Kerry Paterson (Northwestern), Vanessa McBride (OAD), Marc Klein-Wolt (Radboud), Elmar Koerding (Radboud) report on behalf of the MeerLICHT consortium: "The MeerLICHT optical wide-field telescope, located at the Sutherland station of the South African Astronomical Observatory, South Africa, covered the 95% probability-ranked area of the second preliminary skymap of S190814bv [1]. With MeerLICHT's 2.7 square degree field-of-view sampled at 0.56"/pix, a set of 24 fields covered the 95% area. Each field was observed in a set of u, q (440-720nm), i bands in one-minute exposures per filter, starting at 23:11 UT 2019-08-14, and continued throughout the night until dawn at 04:19 UT 2019-08-15. Each field was covered at least twice with a 2-hour time separation. The majority was covered a third time before dawn. Sky conditions were photometric, with a seeing around 2.5" in q-band. Limiting magnitudes (5-sigma point-source) were 18.5 mag (u), 19.7 mag (q) and 19.1 mag (i) in 60s exposures affected by full-moon conditions. Data processing is ongoing and results will be reported when they become available. Monitoring of the updated skymap [2] will continue over the coming nights." The MeerLICHT telescope [3] is designed, built and operated by the MeerLICHT consortium consisting of Radboud University, the University of Cape Town, the Univerity of Oxford, the South African Astronomical Observatory, the University of Manchester and the University of Amsterdam, with support from the Netherlands Research School for Astronomy NOVA, the Netherlands Organisation for Scientific Research NWO, the KU Leuven and the South African Radio Astronomical Observatory. References: [1] LVC Collaboration, GCN Circ. 25324 [2] LVC Collaboration, GCN Circ. 25333 [3] Bloemen et al., 2016, SPIE.9906E..64B //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25341 SUBJECT: LIGO/Virgo S190814bv: No counterpart candidates in the Swift/BAT Observations DATE: 19/08/15 15:01:36 GMT FROM: Amy Lien at GSFC D. M. Palmer (LANL), S. D. Barthelmy (NASA/GSFC), A. Y. Lien (GSFC/UMBC), T. Sakamoto (AGU), A. P. Beardmore (U. Leicester), M. G. Bernardini (INAF-OAB), A. A. Breeveld (MSSL-UCL), D. N. Burrows (PSU), S. Campana (INAF-OAB), S. B. Cenko (NASA/GSFC), G. Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB), V. D'Elia (ASI-SSDC), S. Emery (UCL-MSSL), P. A. Evans (U. Leicester), P. Giommi (ASI), C. Gronwall (PSU), D. Hartmann (Clemson U.), J. A. Kennea (PSU), H. A. Krimm (NSF), N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), J. A. Nousek (PSU), S. R. Oates (Uni. of Warwick), P. T. O'Brien (U. Leicester), J. P. Osborne (U. Leicester), C. Pagani (U. Leicester), K. L. Page (U.Leicester), M. J. Page (UCL-MSSL), M. Perri (ASDC), J. L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU), M. H. Siegel (PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (PSU), E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team: We report the search results in the BAT data within T0 +/- 100 s of the LVC event S190814bv (LIGO/VIRGO Collaboration GCN Circ. 25324), where T0 is the LVC trigger time (2019-08-14T21:10:39.013 UTC). The center of the BAT FOV at T0 is RA = 9.820 deg, DEC = -51.313 deg, and the ROLL angle is 122.517 deg. The BAT Field of View (>10% partial coding) covers 99.80% of the integrated LVC localization probability, and 99.93% of the galaxy convolved probability (Evans et al. 2016). Note that the sensitivity in the BAT FOV changes with the partial coding fraction. Please see the BAT FOV figure in the summary page (link below) for the specific location of the LVC region relative to the BAT FOV. Within T0 +/- 100 s, no significant detections (signal-to-noise ratio >~ 5 sigma) are found in the BAT raw light curves with time bins of 64 ms, 1 s, and 1.6 s. Assuming an on-axis (100% coded) short GRB with a typical spectrum in the BAT energy range (i.e., a simple power-law model with a power-law index of -1.32, Lien & Sakamoto et al. 2016), the 5-sigma upper limit in the 1-s binned light curve corresponds to a flux upper limit (15-350 keV) of ~ 1.17 x 10^-7 erg/s/cm^2. Assuming a luminosity of ~ 2 x 10^47 erg/s (similar to GW170817) and an average Epeak of ~ 400 keV for short GRBs (Bhat et al. 2016), this flux upper limit corresponds to a distance of ~ 66.43 Mpc. No event data are available around T0 +/- 100 s. BAT retains decreased, but significant, sensitivity to rate increases for gamma-ray events outside of its FOV. About 0.11% of the integrated LVC localization probability was outside of the BAT FOV but above the Earth's limb from Swift's location, and the corresponding flux upper limits for this region are within roughly an order of magnitude higher than those within the FOV. The results of the BAT analysis are available at https://swift.gsfc.nasa.gov/results/BATbursts/team_web/S190814bv/web/source_public.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25342 SUBJECT: LIGO/Virgo S190814bv: KMTNet observation DATE: 19/08/15 15:10:26 GMT FROM: Joonho Kim at Seoul National U. Joonho Kim (SNU), Myungshin Im (SNU), Chung-Uk Lee (KASI), Seung-Lee Kim (KASI), Gregory S. H. Paek (SNU), Gu Lim (SNU), Changsu Choi (SNU), Sungyong Hwang (SNU), Sophia Kim (SNU), Bomi Park (SNU), Hyung Mok Lee (KASI), on behalf of a larger collaboration We observed the 90% credible region (~38 deg^2) of the localization map of the NSBH merger candidate, S190814bv (LIGO/Virgo GCN 25324) with KMTNet, Chile (CTIO) starting at 2019-08-15 05:39:26 UT. The images were taken in R-band with 240 sec exposure time to the depth of R ~ 22 mag (5-sigma detection). The central coordinate of each 2 deg x 2 deg pointing is given below. The search for transients is ongoing. target ra dec G347305-0 00:51:43.4 -25:38:02 G347305-1 00:49:44.8 -23:38:02 G347305-2 01:29:07.3 -31:38:02 G347305-3 01:00:31.5 -25:38:02 G347305-4 00:41:04.7 -23:38:02 G347305-5 00:42:55.4 -25:38:02 G347305-6 00:58:24.8 -23:38:02 G347305-7 00:54:03.2 -27:38:02 G347305-8 00:42:44.8 -21:38:02 G347305-9 01:36:01.5 -33:38:02 G347305-10 00:51:17.7 -21:38:02 G347305-11 01:26:31.5 -33:38:02 G347305-12 01:19:49.4 -31:38:02 G347305-13 01:03:00.1 -27:38:02 G347305-14 01:38:25.1 -31:38:02 G347305-15 00:45:06.2 -27:38:02 G347305-16 01:21:13.4 -29:38:02 G347305-17 01:30:20.3 -29:38:02 We thank the KMTNet observers for performing the observation. -- -- Joonho Kim joonho@astro.snu.ac.kr Graduate Student, Astronomy Program, Dept. of Physics & Astronomy, Seoul National University, Seoul, Korea ᐧ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25343 SUBJECT: LIGO/Virgo S190814bv: No candidates from the Zwicky Transient Facility DATE: 19/08/15 16:40:42 GMT FROM: Leo Singer at GSFC Leo P. Singer (NASA GSFC), Mansi M. Kasliwal (Caltech), Michael W. Coughlin (Caltech), Anna Franckowiak (DESY), Robert Stein (DESY), Jannis Necker (DESY), Jesper Sollerman (OKC), Ariel Goobar (OKC), Shreya Anand (Caltech), Tomas Ahumada (UMD), Eric Bellm (UW), Igor Andreoni (Caltech), Dmitry Duev (Caltech), Kishalay De (Caltech), Matt Hankins (Caltech), Danny Goldstein (Caltech), Samaya Nissanke (UofA), Harsh Kumar (IITB), Varun Bhalerao (IITB), Joshua S. Bloom (UCB), David Kaplan (UWM), Daniel A. Perley (LJMU), S. Bradley Cenko (NASA) report on behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations: We observed the localization region of the gravitational wave trigger S190814bv (GCN 25324, GCN 25333) with the Palomar 48-inch telescope equipped with the 47 square degree ZTF camera (Bellm et al. 2019, Graham et al. 2019). The tiling was optimally determined and triggered using the GROWTH Target of Opportunity marshal (Coughlin et al. 2019a, Kasliwal et al. 2019b). We started obtaining target-of-opportunity observations in the g-band, r-band and i-band filters beginning at UT 2019-08-14 10:32 UT. We covered 86% of the enclosed probability before 12-deg twilight and analyzed in real-time. Each exposure was 300s with a typical depth of ~20.3 mag due to the high airmass. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). AMPEL (Nordin et al. 2019) was used to vet candidates based on their light curves. After rejecting stellar sources (Tachibana and Miller 2018) and moving objects and applying machine learning algorithms (Mahabal et al. 2019), and after removing candidates with history of variability prior to the merger time, no high-significance transient candidates were identified by our pipeline in the 90% localization. ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, TTU, and USyd, Australia. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert filtering and follow-up co-ordination is being undertaken by the GROWTH marshal system (Kasliwal et al. 2019). [GCN OPS NOTE(14aug19): Per author's request, the Subject line containing "S190425z" was changed to "S190814bv".] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25344 SUBJECT: LIGO/Virgo S190814bv: no counterpart candidates in Keck I MOSFIRE imaging DATE: 19/08/15 16:57:58 GMT FROM: Jonathan S. Brown at UCSC J. S. Brown, R. J. Foley, D. A. Coulter, C. D. Kilpatrick, K. Siellez, C. Rojas-Bravo, G. Dimitriadis, M. R. Seibert (UCSC), J. S. Bloom, D. Kasen (UCB), and D. A. Howell (LCO/UCSB) Report on behalf of the 1M2H and the UC-NASA-Keck collaborations: In the process of searching the localization region of LIGO/Virgo S190814bv (LIGO/Virgo Collaboration, GCN #25324), we obtained 30-second J-band exposures of the following regions with the Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE) on the Keck I telescope on Maunakea. Observations began at approximately UT 2019-08-15 13:10. The field of view is roughly 6.1'x6.1'. The approximate center of each image is noted in the table below. The first two fields correspond to the fields of DESGW candidates AT2019nme and AT2019nmd, respectively (GCN #25336). The remaining fields were prioritized according to the relative probability of potential host galaxies (Coulter et al. 2017, Science, 358, 1556). Visually inspecting our images and comparing to PS1 and DECaLS images of the same fields, we did not detect any sources in J-band at the expected location of the candidates reported in GCN #25324, nor did we detect any sources without optical counterparts with a limiting magnitude of J~20 mag. RA (J2000) | DEC (J2000) 00 50 32.56 | -22 13 33.70 00 51 29.00 | -22 28 16.96 00 48 21.86 | -25 07 36.52 00 47 05.25 | -24 14 19.32 00 53 57.74 | -24 32 35.30 00 51 29.86 | -24 38 32.97 00 52 41.58 | -25 44 01.86 00 50 56.15 | -23 38 53.38 00 51 18.76 | -26 10 05.01 01 34 29.64 | -32 48 22.46 We thank the staff of Keck observatory including Jim Lyke, John O'Meara, Randy Campbell, and Hilton Lewis for facilitating these Target-of-Opportunity observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25346 SUBJECT: LIGO/Virgo S190814bv: ATLAS forced photometry non-detections of DESGW candidates DATE: 19/08/15 18:07:51 GMT FROM: O. McBrien at QUB O. R. McBrien, S. Srivastav, K. W. Smith, D. R. Young, M. Dobson, S. J. Smartt, J. Gillanders, P. Clark, D. O'Neil, S. Sim (QUB), L. Denneau, H. Flewelling, A. Heinze, J. Tonry, H. Weiland (IfA, Univ. Hawaii), A. Rest (STScI), B. Stalder (LSST), C. Stubbs (Harvard) We report ATLAS (Tonry et al. 2018) forced photometry at the position of the candidate objects reported by the DESGW team (GCN 25336) following the NS-BH event S190814bv (The LIGO Scientific Collaboration and the Virgo Collaboration, GCN 25324). AT2019nmd (desgw-190814a) and AT2019nme (desgw-190814b) were reported in GCN 25336. Both objects were discovered on MJD 58710.278 at coordinates RA=12.870848 deg Dec=-22.471377 deg for AT2019nmd and RA=12.635660 deg Dec=-22.226027 deg for AT2019nme. We have performed forced photometry at the locations of these transients covering the period of time from their discovery epoch to 100 days prior (MJD 58610). The fields of AT2019nmd and AT2019nme were visited on 16 separate nights during this time by ATLAS. A typical observing night sees each field observed 4 – 5 times with 30 second exposures. For both AT2019nmd and AT2019nme we find no significant (SNR > 3 sigma) flux in this time to a limiting magnitude of >19.9 mag and >20.1 mag respectively, mostly in the ATLAS-orange filter, for a typical 30 second exposure. The most recent ATLAS non-detections at the locations of these candidates occur on MJD 58709.630 at >19.5 mag in the ATLAS-cyan filter for AT2019nmd and on MJD 58709.630 at >19.4 mag in the ATLAS-cyan filter (both at a SNR limit of 3 sigma). This work has made use of data from the Asteroid Terrestrial-impact Last Alert System (ATLAS) project. ATLAS is primarily funded to search for near earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; byproducts of the NEO search include images and catalogs from the survey area. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen's University Belfast, and the Space Telescope Science Institute. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25347 SUBJECT: LIGO/Virgo S190814bv: no counterpart candidates in Nickel/Direct imaging and non-detections of 2019nmd and 2019nme DATE: 19/08/15 18:26:40 GMT FROM: Charles Kilpatrick at UC Santa Cruz C. D. Kilpatrick, J. S. Brown, D. A. Coulter, G. Dimitriadis, R. J. Foley, S. A. Medallon, C. Rojas-Bravo, M. R. Siebert, K. Siellez, C. S. Smith (UCSC) report on behalf of the One-Meter Two Hemisphere (1M2H) collaboration: in the process of following up galaxies in the localization region of LIGO/Virgo collaboration event S190814bv (GCN #25324) provided in the updated map of GCN #25333, we observed the following galaxies with the Direct 2k x 2k detector on the 1m Nickel telescope at Lick Observatory, Mt. Hamilton, California on UT 2019 August 15. Each field was targeted toward a galaxy in the localization region and represents a 6.4 arcmin x 6.4 arcmin pointing centered at the indicated coordinates. All images were 2 minute r' band exposures, and we indicate the approximate 3-sigma limiting magnitude of each image. Comparing to PS1 r band images of the same regions, we did not detect any transients to this depth. Object RA Dec MJD Limiting Magnitude LEDA3080215 00:36:02.33 -20:43:20.3 58710.39502 20.3 LEDA835281 00:35:54.70 -20:53:53.5 58710.39831 20.4 LEDA837629 00:41:16.70 -20:43:28.9 58710.40064 20.3 LEDA829060 00:38:23.64 -21:21:54.4 58710.40337 20.3 LEDA840263 00:40:59.47 -20:31:41.2 58710.40575 20.2 LEDA828390 00:42:36.34 -21:24:58.3 58710.40824 20.3 LEDA824045 00:42:38.30 -21:44:54.2 58710.41062 20.3 LEDA823717 00:41:45.22 -21:46:16.3 58710.41345 20.2 LEDA822778 00:42:26.78 -21:50:27.2 58710.41599 20.3 LEDA172750 00:40:30.07 -22:05:42.0 58710.41897 20.2 LEDA818205 00:43:34.03 -22:09:13.3 58710.42163 20.4 LEDA73383 00:39:20.21 -22:05:06.7 58710.42706 20.3 LEDA816845 00:43:06.41 -22:14:40.6 58710.43175 20.2 LEDA828390 00:42:22.94 -21:28:29.6 58710.43416 20.2 LEDA133689 00:44:16.85 -22:19:40.1 58710.43689 20.2 LEDA817925 00:43:33.31 -22:10:14.2 58710.44282 20.4 00430218-2231305 00:43:02.19 -22:31:30.6 58710.44549 20.3 LEDA818175 00:43:23.02 -22:09:11.5 58710.44801 20.3 00512962-2216458 00:51:29.62 -22:16:45.8 58710.45080 20.3 LEDA817340 00:43:42.60 -22:12:33.5 58710.45368 20.3 LEDA820155 00:46:59.40 -22:00:56.9 58710.45629 20.3 LEDA822779 00:45:59.40 -21:50:06.7 58710.45894 20.4 LEDA820466 00:45:16.94 -21:59:40.6 58710.46148 20.4 LEDA828872 00:42:20.18 -21:22:19.9 58710.46386 20.3 LEDA821974 00:48:08.33 -21:53:30.5 58710.46636 20.3 LEDA825694 00:51:51.00 -21:37:09.1 58710.47198 20.4 LEDA826986 00:49:49.08 -21:30:52.9 58710.47496 20.4 LEDA830067 00:48:30.05 -21:16:42.6 58710.47782 20.3 In addition, we observed the fields around DESGW transients (GCN #25336) 2019nmd and 2019nme. 2019nmd was observed in i' band for 10 minutes and 2019nme was observed in i' for 5 minutes. At the time of observations, we did not detect either transient to the approximate 3-sigma limiting magnitude indicated below. Object RA Dec MJD Limiting Magnitude 2019nmd 00:51:35.95 -22:27:02.5 58710.48096 20.6 2019nme 00:50:39.65 -22:12:17.6 58710.49475 20.3 For 2019nmd, our limits are comparable to the discovery magnitude and in the same band as the original report of GCN #25336. However, for 2019nme our limits are significantly deeper than the discovery report, which suggests that this transient is either extremely rapidly declining in i' band (1 mag in the 5.2 hours between DESGW and Nickel observations), an uncatalogued minor planet, or non-astrophysical in nature. Please direct all communication related to this circular to Charles Kilpatrick (cdkilpat@ucsc.edu) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25348 SUBJECT: LIGO/Virgo S190814bv: des-gw190814a is consistent with an asteroid DATE: 19/08/15 19:00:13 GMT FROM: Mansi M. Kasliwal at Caltech/Carnegie K. De (Caltech), D. Goldstein (Caltech), I. Andreoni (Caltech), S. B. Cenko (NASA GSFC), J. Bloom (UCB), D. A. Perley (LJMU), M. M. Kasliwal (Caltech) report on behalf of the Global Relay of Observatories Watching Transients Happen (GROWTH) collaboration We report that the position and time of desgw-190814a (GCN 25336) is consistent with a known asteroid (297025) 2010 GA33. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25349 SUBJECT: LIGO/Virgo S190814bv: No counterpart candidates in TOROS observations DATE: 19/08/15 20:02:12 GMT FROM: Richard Camuccio at TOROS Mario Diaz (UTRGV/CGWA), Diego Garcia Lambas (IATE), Lucas Macri (TAMU), Jose Luis Nilo Castellon (Univ La Serena), Omar Lopez-Cruz (UNAM) Richard Camuccio (UTRGV/CGWA), Elizabeth Caputa (Missouri S&T), Wendy Mendoza (UTRGV/CGWA) are reporting on behalf of the TOROS collaboration. We report the following targeted observations for S190814bv conducted by the Cristina Torres Memorial Observatory (CTMO) in Brownsville, Texas: HyperLEDA 787700: RA: 12.874431 deg Dec: -24.642494 deg HyperLEDA 3235460: RA: 13.3533 deg Dec: -25.1578 deg HyperLEDA 3235474: RA: 13.2654 deg Dec: -25.1785 deg HyperLEDA 3235463: RA: 13.3238 deg Dec: -25.1856 deg HyperLEDA 777629: RA: 12.8241 deg Dec: -25.55379 deg HyperLEDA 788830: RA: 13.490571 deg Dec: -24.543142 deg ESO474-035: RA: 13.173257 deg Dec: -25.733852 deg HyperLEDA 3235467: RA: 13.3267 deg Dec: -25.6538 deg HyperLEDA 3235506: RA: 12.5911 deg Dec: -25.0564 deg HyperLEDA 786999: RA: 13.269273 deg Dec: -24.704401 deg Observations were conducted on 2019-08-15 from 07:00 to 09:00 UT using the CTMO CDK17 optical astrograph with an Apogee Alta F16M CCD. Fields are 43 arcminutes FOV, 2x2 binning, unfiltered, median-stacked 60-sec exposures (5 images per series). Source search is ongoing and we will report on any positive detections. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25350 SUBJECT: LIGO/Virgo S190814bv: no counterpart candidates in Swope imaging DATE: 19/08/15 21:09:07 GMT FROM: Charles Kilpatrick at UC Santa Cruz C. D. Kilpatrick, D. A. Coulter, J. S. Brown, G. Dimitriadis, R. J. Foley, C. Rojas-Bravo, M. R. Siebert, K. Siellez (UCSC), A. L. Piro (Carnegie), A. Rest (STScI), Natalie Ulloa (Universidad de La Serena), M. Drout (University of Toronto) report on behalf of the One-Meter Two Hemisphere (1M2H) collaboration: in the process of following up the localization region of LIGO/Virgo collaboration (LVC) event S190814bv (GCN #25324), we observed the following fields with the 1.0-m Swope telescope at Las Campanas Observatory, Chile on UT 2019 August 15. We covered approximately 42.1% of the probability region from the LALinference map provided by the LVC in GCN #25333. The Swope Direct 4k x 4k imager covers 29.8 arcmin x 29.7 arcmin. All images were 2 minute r-band exposures. For each image, the approximate pointing center and 3-sigma limiting magnitude are indicated. Using the photpipe image reduction and subtraction pipeline (Rest et al. 2005, ApJ, 634, 1103), we compared our images to publicly available DECam r-band images of the same fields. We did not detect any new transients in these images. Field RA Dec MJD Limiting Magnitude s047243 00:49:28.13 -25:46:43.7 58710.22978 20.4 s047244 00:51:40.99 -25:47:16.8 58710.23631 21.0 s047897 00:47:02.64 -25:17:41.6 58710.24059 20.9 s038397 01:35:18.38 -32:43:43.7 58710.24462 21.0 s046590 00:49:38.62 -26:16:34.0 58710.24954 20.8 s038395 01:30:36.48 -32:43:46.9 58710.26314 19.9 s046591 00:51:50.90 -26:16:30.4 58710.26905 19.8 s037786 01:31:03.31 -33:13:26.4 58710.27448 19.7 s051884 00:43:53.16 -22:18:36.4 58710.28009 19.7 s039006 01:27:41.83 -32:14:13.6 58710.28429 20.1 s050547 00:50:37.25 -23:17:55.0 58710.28807 19.6 s047241 00:45:06.91 -25:47:25.4 58710.29461 20.6 s038396 01:32:58.15 -32:43:38.3 58710.29737 20.0 s038394 01:28:15.17 -32:43:40.1 58710.30383 19.8 s045940 00:49:53.81 -26:46:48.4 58710.31389 20.3 s039625 01:34:14.54 -31:44:16.4 58710.31954 20.3 s046592 00:54:03.50 -26:17:03.5 58710.32758 20.3 s049881 00:50:51.60 -23:48:09.0 58710.33806 17.6 s039007 01:30:01.97 -32:14:17.2 58710.34484 18.9 s039623 01:29:35.64 -31:44:06.7 58710.34875 19.5 s049883 00:55:09.22 -23:47:24.0 58710.35221 19.0 s047896 00:44:53.88 -25:17:20.0 58710.35535 18.9 s050543 00:41:59.93 -23:18:22.0 58710.36199 19.8 s051883 00:41:44.54 -22:18:59.0 58710.36544 20.6 s049880 00:48:39.94 -23:48:07.2 58710.37390 19.9 s047901 00:55:50.47 -25:17:21.8 58710.37663 19.0 s040862 01:23:59.14 -30:44:52.4 58710.38109 19.7 s037787 01:33:26.71 -33:13:12.7 58710.38419 20.5 s040240 01:24:31.44 -31:13:48.7 58710.38748 20.7 s051885 00:46:00.48 -22:18:24.1 58710.39168 19.8 s051217 00:52:36.22 -22:48:37.8 58710.39462 20.0 s048553 00:42:30.31 -24:46:55.2 58710.39748 19.6 s047242 00:47:17.16 -25:47:08.5 58710.40022 19.5 s050549 00:54:53.54 -23:18:23.8 58710.40316 20.6 s037788 01:35:45.82 -33:13:21.7 58710.40647 19.7 s052557 00:43:40.08 -21:49:19.6 58710.40962 19.6 s046589 00:47:25.87 -26:16:54.1 58710.41251 19.5 s045941 00:52:02.76 -26:47:29.0 58710.41605 21.5 s047895 00:42:41.18 -25:17:03.5 58710.41941 20.0 s038393 01:25:53.35 -32:43:38.3 58710.42301 21.1 s038392 01:23:31.13 -32:43:27.8 58710.42620 20.6 s050546 00:48:25.37 -23:18:02.9 58710.43197 20.3 s048552 00:40:17.18 -24:47:48.5 58710.43449 19.9 s049878 00:44:19.54 -23:47:55.0 58710.43701 19.8 s040243 01:31:26.30 -31:14:22.9 58710.43999 20.4 s046594 00:58:25.85 -26:16:35.0 58710.44370 20.1 Please direct all communication related to this circular to Charlie Kilpatrick (cdkilpat@ucsc.edu). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25351 SUBJECT: LIGO/Virgo S190814bv: no counterpart candidates in Thacher imaging DATE: 19/08/15 21:12:41 GMT FROM: Charles Kilpatrick at UC Santa Cruz J. Swift, Y. Yin (Thacher School Observatory), C. D. Kilpatrick, J. S. Brown, D. A. Coulter, G. Dimitriadis, R. J. Foley, C. Rojas-Bravo, M. R. Siebert, K. Siellez (UCSC) report on behalf of the One-Meter Two Hemisphere (1M2H) collaboration: in the process of following up galaxies in the localization region of LIGO/Virgo collaboration event S190814bv (GCN #25324) provided in the updated map of GCN #25333, we observed the following fields with the 0.7-m Thacher telescope at the Thacher School Observatory on UT 2019 August 15. Each field represents a 3 minute r-band image. The approximate center of each image is noted in the table below, and the field of view is a 21 arcmin x 21 arcmin rectangle. We also note the approximate 3-sigma limiting magnitude of each pointing. Comparing our images to PS1 r-band images of the same fields, we did not detect any transient sources. Field RA Dec MJD Limiting Magnitude t100590 00:46:22.72 -24:24:13.7 58710.46465 19.3 t111134 00:36:17.38 -20:34:58.4 58710.45696 19.3 t106304 00:39:41.83 -22:18:48.6 58710.45951 19.4 t108232 00:42:30.94 -21:37:16.0 58710.46209 19.3 t102488 00:49:11.40 -23:41:53.2 58710.46721 19.2 t104397 00:53:26.90 -23:00:19.8 58710.46976 19.2 t099651 00:54:10.94 -24:44:11.0 58710.47230 19.1 t102491 00:53:44.16 -23:41:53.5 58710.50424 19.3 t105354 00:53:20.71 -22:39:33.8 58710.50678 19.1 t103442 00:52:06.82 -23:21:06.1 58710.50934 19.1 Please direct all communication related to this circular to Charlie Kilpatrick (cdkilpat@ucsc.edu). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25352 SUBJECT: LIGO/Virgo S190814bv: No Counterparts in DDOTI/OAN Optical Observations DATE: 19/08/15 21:47:51 GMT FROM: Simone Dichiara at UMCP/NASA/GSFC Simone Dichiara (GSFC/UMD), Margarita Pereyra (UNAM), Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), Diego Gonzalez (UNAM), Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM), Eleonora Troja (GSFC/UMD), Gabriele Minervini (INAF/IAPS-Rome) and Tanner Wolfram (ASU) report: We observed LIGO/Virgo S190814bv (Mo et al, GCN Circ. 25324) with the DDOTI/OAN wide-field imager at the Observatorio Astronomico Nacional on Sierra San Pedro Martir (http://ddoti.astroscu.unam.mx) on the night of 2019-08-15 UTC. We observed approximately 100 square degrees with three visits centered on 00:51:19.690 -25:14:28.9, 00:50:55.478 -27:15:38.84, and 00:52:24.972 -22:31:44.59, respectively. These regions include about 90% of the probability in the updated localization map (Mo et al, GCN Circ. 25333). We observed from 2019-08-15 07:58 UTC to 2019-08-15 11:52 UTC (10.8 to 14.7 hours after the event). We obtained about 20 minutes total exposure on each field in the w filter. We calibrate our images against the APASS catalog. Our 10-sigma limiting magnitude are typically w = 18.0 AB. Comparing our 10-sigma detections against the USNO-B1 catalog, we detect no uncataloged sources with significant fading. We thank the staff of the Observatorio Astronomico Nacional in San Pedro Martir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25353 SUBJECT: LIGO/Virgo S190814bv: No counterpart candidates in KAIT observations DATE: 19/08/15 21:52:53 GMT FROM: Weikang Zheng at UC Berkeley Sergiy Vasylyev, Benjamin Stahl, Keto D. Zhang, Thomas de Jaeger, Yukei Murakami, Shaunak Modak, Kishore Patra, James Sunseri, Nachiket Girish, WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of Lick/KAIT GW follow-up team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, observed the 90% region of the gravitationa-wavei event S190814bv (GCN 25324) detected by LIGO/Virgo. More than one thousand galaxies were selected from the Glade catalog V1.0 (Dalya et al., 2018, MNRAS, 479, 2374; http://aquarius.elte.hu/glade/) according to their priority score. KAIT observed 161 of them based on their priority scores and elevation visibility, with each clear-filter exposure time being 60 s. The first image was taken at 08:48:31, Aug. 15th UT, about 11.63 hours after the trigger, and the last image at 12:36:25 UT. Our typical limiting mag is 18.0. No viable counterparts were identified and the analysis is ongoing. A full list of galaxies observed by KAIT is given below. GladeID UT(Aug15) RA_J2000 Dec_J2000 ----------------------------------------------- G0617334 08:48:31 00:02:55.836 -26:54:50.5692 G0791605 08:49:41 00:02:57.7046 -26:57:24.5772 G0789819 08:50:50 00:03:01.0733 -27:08:06.576 G0558411 08:51:59 00:04:08.8922 -28:49:13.5444 G0809614 08:53:09 00:04:40.2163 -27:21:49.0536 G0569517 08:54:18 00:07:09.258 -25:50:12.2712 G0554559 08:55:25 00:07:13.8041 -26:45:13.2732 G0552162 08:56:35 00:08:48.9797 -25:44:53.5596 G0816044 08:57:44 00:10:35.6849 -25:20:07.062 G0662146 08:58:53 00:10:43.2523 -25:05:45.3336 G0706271 09:00:03 00:10:53.6309 -25:17:14.3628 G0572323 09:01:12 00:11:24.8933 -24:58:22.854 G0804920 09:02:21 00:11:50.3609 -25:18:43.344 G0842323 09:08:13 00:34:13.637 -21:26:19.0428 G0688940 09:09:22 00:35:51.1817 -23:00:22.6044 G0394081 09:10:31 00:36:23.0861 -23:01:00.7212 G0817956 09:11:41 00:36:58.2924 -24:36:18.3348 G0743219 09:12:50 00:36:59.5889 -22:30:52.2324 G0573758 09:13:59 00:37:57.617 -25:04:25.4424 G0578034 09:15:09 00:38:07.3318 -25:04:03.3888 G0591251 09:16:18 00:38:21.702 -22:20:40.2792 G0478277 09:19:46 00:39:04.2689 -23:56:02.3532 G0738560 09:20:55 00:39:07.4071 -22:18:43.9848 G0763481 09:22:05 00:39:08.2001 -22:20:00.9852 G0811260 09:23:14 00:39:11.9921 -23:22:28.9776 G0745005 09:24:21 00:39:13.7374 -22:06:07.974 G0790001 09:25:31 00:39:30.8659 -25:41:48.3216 G0757125 09:26:40 00:39:35.2282 -22:08:28.8528 G0748966 09:27:49 00:39:40.8425 -22:11:46.8528 G0678245 09:28:59 00:39:48.9946 -24:36:05.2668 G0743081 09:30:08 00:39:58.4004 -22:29:26.43 G0875451 09:31:17 00:40:03.0533 -23:53:05.4456 G1335254 09:32:27 00:40:05.9028 -22:49:32.4408 G1043206 09:33:40 00:40:21.3828 -24:40:09.3 G0579686 09:34:49 00:40:46.848 -21:55:33.2652 G0557014 09:35:59 00:40:58.2617 -22:04:59.2608 G0621627 09:37:08 00:41:02.3038 -25:13:02.9676 G0765905 09:38:17 00:41:32.0467 -22:38:37.9032 G0642650 09:39:27 00:42:04.0092 -21:22:17.49 G0721087 09:40:36 00:42:10.4618 -23:35:29.4864 G0665083 09:41:45 00:42:16.4966 -21:46:26.4684 G0676836 09:48:00 00:42:16.6445 -21:49:34.4676 G0723410 09:49:10 00:42:33.3876 -22:51:58.7088 G0669913 09:50:19 00:42:39.9372 -21:48:00.7056 G0670225 09:51:28 00:42:42.3053 -21:46:26.6952 G0710305 09:52:38 00:42:54.6986 -22:15:09.5796 G0580725 09:53:47 00:43:26.9477 -22:11:22.4916 G0702909 09:54:56 00:44:10.5792 -22:20:48.426 G0759372 09:56:06 00:44:14.1631 -25:06:33.2676 G0551250 09:57:15 00:44:29.508 -23:17:49.5312 G0818878 09:58:22 00:44:48.4951 -22:06:59.5188 G0639370 09:59:32 00:44:50.5433 -23:09:32.5044 G0667923 10:00:41 00:45:06.4044 -22:07:11.9064 G0669318 10:01:50 00:45:15.4805 -20:43:47.8956 G0721969 10:03:03 00:45:53.2922 -23:46:20.8596 G0277847 10:04:12 00:45:58.6939 -21:38:19.3416 G0006543 10:05:21 00:45:59.4336 -26:30:17.7228 G0791080 10:06:33 00:46:10.4158 -24:39:00.6912 G0739058 10:07:42 00:46:16.8151 -24:16:45.606 G0705242 10:10:03 00:47:05.2543 -24:14:19.3308 G0693544 10:11:12 00:47:07.5271 -24:22:14.3292 G0643115 10:12:21 00:47:28.1918 -23:01:22.836 G0600781 10:13:31 00:47:28.9483 -25:26:26.358 G1062310 10:14:40 00:47:46.6894 -25:02:49.3116 G0720274 10:15:49 00:48:16.4729 -21:31:56.8452 G0750475 10:16:58 00:48:21.859 -25:07:36.5304 G0744205 10:18:08 00:48:29.0066 -22:08:50.7984 G0672984 10:19:17 00:48:29.9995 -21:21:37.7928 G1177675 10:20:26 00:48:35.9251 -21:21:56.052 G0682460 10:21:42 00:48:43.2874 -23:33:42.0696 G0641017 10:23:35 00:00:31.5545 -28:29:15.072 G0414879 10:24:44 00:01:18.1718 -27:25:23.646 G0719412 10:25:54 00:01:37.9354 -27:33:57.1896 G0968549 10:27:03 00:02:11.4245 -28:54:53.9964 G0654194 10:28:10 00:03:58.4671 -28:36:55.5732 G0626760 10:29:19 00:06:59.7509 -26:56:15.2484 G0913496 10:30:29 00:08:54.3425 -30:02:47.8968 G0555127 10:31:40 00:13:02.9052 -24:12:52.5024 G0681282 10:32:49 00:14:33.5014 -24:42:09.7452 G0231439 10:33:59 00:15:05.7511 -24:41:29.7888 G0279898 10:35:08 00:15:10.9656 -23:52:55.1172 G0654042 10:36:17 00:17:23.1067 -23:34:59.5272 G0579242 10:37:27 00:17:31.7258 -24:13:24.1176 G0624710 10:38:36 00:24:11.2325 -23:56:29.5836 G0823635 10:39:47 00:30:01.7892 -20:33:30.2364 G0626107 10:40:57 00:31:08.0801 -22:37:07.2804 G0201978 10:42:06 00:31:20.4821 -26:15:39.7512 G0557297 10:43:19 00:34:08.2654 -21:26:08.0664 G0842323 10:44:29 00:34:13.637 -21:26:19.0428 G1238848 10:45:38 00:35:23.8824 -24:00:06.4548 G0685281 10:46:49 00:36:13.5293 -19:07:52.6044 G1381770 10:48:03 00:37:34.5636 -30:49:46.4484 G1641250 10:49:16 00:38:22.164 -18:51:54.936 G0504091 10:50:25 00:46:49.338 -16:04:01.6428 G0822251 10:51:35 00:46:56.9594 -17:38:19.6368 G0622610 10:52:48 00:48:15.6694 -32:56:55.7988 G0808228 10:53:57 00:49:49.535 -28:55:06.9204 G1216190 10:55:09 00:50:22.1868 -19:16:50.1996 G1483945 10:56:18 00:55:02.856 -19:00:19.44 G0608608 10:57:41 00:56:04.205 +26:18:18.7236 G0014217 11:03:46 00:48:58.3279 -25:41:38.1048 G0719585 11:04:57 00:49:14.671 -23:51:30.7692 G0710791 11:06:07 00:49:16.8218 -26:13:09.0444 G0757091 11:07:16 00:49:19.6882 -26:28:35.0292 G0769196 11:08:27 00:49:23.1202 -26:30:26.9928 G0641513 11:09:37 00:49:27.5539 -26:32:17.8836 G0499986 11:10:48 00:49:42.1651 -21:32:06.5436 G0705726 11:11:59 00:49:46.0318 -26:26:34.9332 G0728436 11:13:11 00:50:29.9453 -21:15:27.1764 G0743489 11:14:22 00:50:39.8738 -26:48:48.222 G0712628 11:15:31 00:50:46.5228 -21:35:13.7976 G0777347 11:16:41 00:50:53.5632 -21:53:57.7932 G0761599 11:17:52 00:51:21.179 -26:59:22.02 G0713331 11:19:03 00:52:06.5686 -22:40:48.666 G0588271 11:20:14 00:52:14.9993 -27:19:41.43 G0743658 11:21:24 00:52:46.1731 -22:58:30.0648 G0497808 11:22:33 00:52:53.6832 -22:26:14.0604 G0772386 11:23:40 00:53:18.4649 -21:41:41.766 G0568027 11:24:50 00:53:25.5694 -21:44:11.7636 G0624396 11:26:03 00:53:28.6651 -21:54:40.752 G0722022 11:27:12 00:53:44.8306 -27:36:18.306 G0747211 11:28:22 00:53:47.3417 -23:19:50.7396 G0696800 11:29:33 00:53:54.5086 -24:04:37.3152 G0124492 11:30:42 00:53:59.7797 -21:40:37.722 G0620268 11:31:52 00:54:07.4657 -21:42:50.5548 G0589142 11:33:07 00:54:20.5241 -23:33:08.586 G0801449 11:34:16 00:54:32.8094 -23:29:41.5644 G0577578 11:35:26 00:54:49.1333 -26:22:16.5216 G1662362 11:36:35 00:55:01.776 -25:07:09.3 G0816374 11:37:44 00:55:04.23 -23:31:29.676 G1423609 11:56:41 00:55:09.1514 -25:27:20.5344 G0660900 11:57:54 00:55:13.5341 -26:19:16.5108 G0930333 11:59:04 00:57:01.1189 -23:50:14.2692 G0127942 12:00:13 00:57:17.6112 -24:00:02.484 G0736225 12:01:22 00:57:46.9243 -27:30:05.85 G0788241 12:02:32 00:58:24.0614 -23:13:29.6724 G0648787 12:03:45 00:58:52.3109 -28:18:11.4696 G0744674 12:04:54 00:59:12.2695 -26:28:32.5092 G0767644 12:06:04 00:59:47.682 -27:07:15.0708 G0678447 12:07:13 01:00:12.6631 -25:29:38.6376 G0508869 12:08:22 01:02:10.9078 -28:24:58.8852 G0663847 12:09:32 01:02:47.4468 -29:26:59.55 G0762311 12:10:43 01:06:12.2227 -30:10:41.1744 G0621801 12:11:52 01:08:06.253 -27:37:43.3704 G0577773 12:13:02 01:08:09.0478 -28:31:25.3776 G0000506 12:14:12 01:10:35.6126 -30:13:16.5576 G0557353 12:15:21 01:11:01.1239 -30:26:18.6324 G0661968 12:16:31 01:13:47.2512 -31:44:50.0928 G0809212 12:17:40 01:15:03.9266 -31:47:01.8024 G0654768 12:18:49 01:15:28.2518 -30:22:28.0344 G0789210 12:19:59 01:15:51.612 -31:35:22.8732 G0798266 12:21:08 01:17:59.3158 -30:45:45.4284 G0820330 12:22:17 01:18:15.4531 -30:46:28.4592 G0783834 12:23:27 01:19:47.6698 -33:04:59.9808 G0569298 12:24:36 01:20:15.8002 -30:11:07.9224 G0620221 12:25:47 01:22:11.3681 -31:32:34.5444 G0818640 12:26:57 01:22:29.1362 -32:43:02.0496 G0657724 12:28:06 01:22:32.7113 -29:58:57.054 G0577695 12:29:18 01:23:01.4191 -31:08:15.5724 G0595298 12:30:27 01:23:14.8567 -32:50:28.6008 G1019706 12:36:25 01:23:40.9826 -31:20:33.5328 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25354 SUBJECT: LIGO/Virgo S190814bv Global MASTER-Net observations report DATE: 19/08/15 22:05:15 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias) D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University) MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the LIGO/Virgo S190814bv errorbox 92 sec after trigger time at 2019-08-15 21:40:44 UT, with upper limit up to 17.6 mag. The observations began at zenit distance = 78 deg. The sun altitude is -32.7 deg. MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) started inspect of the LIGO/Virgo S190814bv errorbox 174 sec after trigger time at 2019-08-15 21:42:06 UT, with upper limit up to 15.5 mag. The observations began at zenit distance = 64 deg. The sun altitude is -67.2 deg. The galactic latitude b = -60 deg., longitude l = 98 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/ligo_1.php?id=10709 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 183 | 2019-08-15 21:40:44 | MASTER-Kislovodsk | ( 0h 47m 29.97s , -25d 48m 07.68s) | C | 180 | 17.2 | 183 | 2019-08-15 21:40:44 | MASTER-Kislovodsk | ( 0h 56m 30.50s , -26d 16m 00.82s) | C | 180 | 17.1 | 264 | 2019-08-15 21:42:06 | MASTER-SAAO | ( 1h 51m 03.49s , -34d 3m 17.86s) | C | 180 | 15.5 | 401 | 2019-08-15 21:44:22 | MASTER-Kislovodsk | ( 0h 38m 07.88s , -24d 15m 24.80s) | C | 180 | 17.6 | 401 | 2019-08-15 21:44:22 | MASTER-Kislovodsk | ( 0h 29m 14.72s , -23d 47m 50.58s) | C | 180 | 17.5 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25355 SUBJECT: LIGO/Virgo S190814bv: des-gw190814b is a moving object DATE: 19/08/15 23:05:10 GMT FROM: Daniel Goldstein at Caltech D. A. Goldstein (Caltech), D. Perley (LJMU), I. Andreoni (Caltech), and M. M. Kasliwal (Caltech) report on behalf of the Global Relay of Observatories Watching Transients Happen (GROWTH) collaboration We processed the public data obtained by the DESGW team described in GCN 25336 using the image subtraction pipeline described in Goldstein, Andreoni et al. (2019) and Andreoni, Goldstein et al. (2019). By examining the subtractions in the vicinity of the optical counterpart candidate des-gw190814b (GCN 25336), we observed that the object is moving by 14.3 arcseconds per hour, in the same direction, in both the i- and z-bands. Based on this information it is very likely that this object is a Solar System Object, and thus is unrelated with the S190814bv gravitational wave event (GCN #25324). The object is not listed in the Minor Planet Center. Visual evidence of the object's motion can be seen at this link: http://astro.caltech.edu/~danny/static/desgw-180814b.001.png GROWTH is a worldwide collaboration comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, TTU, and USyd, Australia. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. We gratefully acknowledge Amazon, Inc. for a generous grant that funded our use of the Amazon Web Services cloud computing infrastructure to process the DECam data. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25356 SUBJECT: LIGO/VIRGO S190814bv: No candidates from Pan-STARRS and non-detection of AT2019nme DATE: 19/08/15 23:15:05 GMT FROM: Stephen Smartt at Queen's U/Belfast M. Huber (IfA, Univ. of Hawaii), K. W. Smith (QUB), K. Chambers, A. Schulz (IfA), S. Smartt, D. R. Young, O. McBrien, J. Gillanders. S. Srivastav, D. O'Neil, P. Clark, S. Sim (QUB), T. de Boer, J. Bulger, J. Fairlamb, M. Huber, C.-C. Lin, T. Lowe, E. Magnier, R. J. Wainscoat, M. Willman (IfA, Univ. of Hawaii), T.-W, Chen (MPE), A. Rest (STScI), C. Stubbs (Harvard) We report observations of the LALInference skymap of the NSBH event S190814bv (The LIGO Scientific Collaboration and the Virgo Collaboration, 25333, 25324) with the Pan-STARRS1 telescope (Chambers et al. 2016, arXiv:1612.05560C). Images were taken in the PS1 i and z bands (Tonry et al. 2012, ApJ 750, 99). Beginning at 2019-08-15 12:40:37 UT (58710.5282) or 15.5hrs after the detection of S190814bv, observations started in the i-band. We used the updated LALInference.v1.fits.gz map for pointing coverage. Observations finished at 2019-08-15 15:13:38 UT. At each pointing position a dithered sequence of 45 sec i-band and z-band images were taken. These were combined into a single night stack, covering the GPC1 camera chip gaps. These dithered sequences were repeated, with overlaps, to map 18 square degrees of the LALInference.v1.gz map 90% credible region, corresponding to a summed probability 89% of the skymap. We did not cover the smaller probability blob to the south east at DEC=-32. Conditions were somewhat affected by clouds, and moon, seeing was around 1.2 - 1.3 arcsec. 5-sigma limiting magnitudes were around i ~ 20.8 and z ~ 20.3. The images were processed with the IPP (Magnier et al. 2016, arXiv:1612.05240) and difference images were produced using the Pan-STARRS1 Science Consortium 3Pi images as reference frames. Transient candidates were run through our standard filtering procedures, combined with a machine learning algorithm (Wright et al. 2015, MNRAS, 449, 451) were applied and all candidates were spatially cross-matched with known minor planets, and major star, galaxy, AGN and multi-wavelength catalogues (as described in Smartt et al. 2016, MNRAS, 462 4094), and already reported transients in the TNS before S190814by. After removing these, and requiring detections in BOTH i and z-band stacks, we were left with two transients. Both of which we discount as possible counterparts. Name | TNS Name | RA (J2000) | Dec (J2000) | Disc MJD | i Mag err | z Mag err PS19epf | AT2019noq | 00 48 47.88 | -25 18 23.4 | 58710.58 | 19.93 0.11 | 20.17 0.16 PS19eph | AT2019nor | 00 49 51.99 | -24 16 17.7 | 58710.59 | 19.69 0.07 | 19.55 0.07 PS19epf is within the inner 20% contour. It is located 0.46"S 3.96"E from the centre of the galaxy PSO J012.1980-25.3064 (r = 18.3 Kron mag). The host has no measured photometric or spectroscopic redshift. However there are 4 separate, single night detections in the ZTF public stream, from Lasair (Smith et al. 2019; https://lasair.roe.ac.uk/object/ZTF19abkhnce/), across the last 12 days. Hence it is most probably a SN exploding before the GW. PS19eph is within the inner 10% contour. However it is coincident with the core of the B=18.67 galaxy 6dF J0049520-241618 at z = 0.436522 from NED, and hence is not likely related to S190814bv. We do not recover desgw-190814b (AT2019nme). Reported at i=19.33 z=19.39, (58710.278) by Soares-Santos et al. GCN 25336. This is on the edge of our stack, but we estimate a 3-sigma limit of i~20.6 z~20.2. If it is real, it implies a very fast fade in i-band of 1 mag in about 8hrs. Deeper follow-up is required, and confirmation from the DECam team if it is real. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25358 SUBJECT: LIGO/Virgo S190814bv: No Candidates Found in Wide-Field Infrared Search with Palomar Gattini-IR DATE: 19/08/16 04:21:03 GMT FROM: Matthew Hankins at Caltech M. Hankins (Caltech), K. De (Caltech), M. Coughlin (Caltech), M. M. Kasliwal (Caltech), S. M. Adams (Caltech), I. Andreoni (Caltech), S. Anand (Caltech), M. Sharma (Caltech), L. Singer (NASA GSFC), T. Ahumada (UMD), A. Moore (ANU), J. Soon (ANU), M. Ashley (UNSW), T. Travouillon (ANU) report on behalf of the Palomar Gattini-IR team and the larger GROWTH (Global Relay of Observatories Watching Transients Happen) collaboration We report wide-field near-infrared follow-up observations of the localization region of the gravitational wave event S190814bv (GCN 25324, GCN 25333) by the Palomar Gattini-IR survey (Moore and Kasliwal 2019). Gattini-IR is a newly commissioned near-IR camera with a field of view of 25 square degrees mounted on a robotic 30 cm telescope at Palomar observatory. We started customized Target of Opportunity observations at UT 2019-08-15 08:07. The tiling was optimally determined and triggered using the GROWTH Target of Opportunity marshal (Coughlin et al. 2019a, Kasliwal et al. 2019b). We imaged a total of 95.9 square degrees, covering 89.5% of the probability region of the event for 4 to 7 epochs until UT 2019-08-15 12:09. Each field visit consisted of a sequence of 50 dithered images each with 8 second exposures. These data were processed and stacked with the Palomar Gattini-IR data reduction pipeline (De et al., in prep.). The typical limiting magnitude of each field visit (400s second exposure time) was between 16.5 and 17.0 AB mag in J-band. The average limiting magnitude from stacking all data taken during these observations is ~ 17.5 AB mag in J-band. No viable counterparts without previous history of variability were identified in the single epoch stacks within the survey region. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25359 SUBJECT: LIGO/Virgo S190814bv: No Counterpart Candidates in Las Cumbres Observatory Galaxy Targeted Search DATE: 19/08/16 05:12:19 GMT FROM: Daichi Hiramatsu at Las Cumbres Observatory Daichi Hiramatsu (LCO/UCSB), D. Andrew Howell (LCO/UCSB), Curtis McCully (LCO), Iair Arcavi (Tel Aviv University), Jamison Burke (LCO/UCSB), David Sand (U. Arizona), and Stefano Valenti (UC Davis) on behalf of the Las Cumbres GW Follow-up Collaboration We report 300s g- and i-band images of the following galaxies (obtained from the GLADE 2.3 catalog) in the LIGO/Virgo S190814bv initial localization region (GCN 25324) with the Las Cumbres Observatory 1m telescopes (FoV of 26’.5 x 26’.5) at Sutherland, South Africa and CTIO, Chile. We find no obvious candidates after performing image subtraction using PS1 template images or from visual inspection (denoted by a *) where template images are not available. GLADE-ID RA Dec MJD FILTER Lim-mag 79405 15.666673 -21.336044 58710.04920 i 20.52 79405 15.666673 -21.336044 58710.05415 i 20.50 135569 20.613979 -12.952553 58710.00876 i 20.21 135569 20.613979 -12.952553 58710.14986 i 21.11 23208 17.809616 -16.265219 58710.00875 i 20.46 23208 17.809616 -16.265219 58710.10881 i 19.61 23208 17.809616 -16.265219 58710.10942 i 21.11 20841 5.150148 -31.371368 58710.03911 i 20.78 * 20841 5.150148 -31.371368 58710.12227 i 17.38 * 10009 15.008555 -21.488472 58710.07702 i 21.20 10009 15.008555 -21.488472 58710.08521 i 20.71 10009 15.008555 -21.488472 58710.08857 i 21.04 19184 11.781363 -24.370647 58709.94641 g 19.29 19184 11.781363 -24.370647 58709.95037 i 18.49 21667 19.349241 -16.062389 58709.99357 i 19.31 21667 19.349241 -16.062389 58710.05922 i 20.36 11973 21.889231 -4.682927 58710.09365 i 21.75 11973 21.889231 -4.682927 58710.09864 i 21.77 17507 21.317556 -11.913936 58709.97839 g 19.48 17507 21.317556 -11.913936 58709.98234 i 18.93 17507 21.317556 -11.913936 58710.11725 i 21.33 17507 21.317556 -11.913936 58710.13973 i 20.84 100797 11.870618 -25.440655 58709.98863 i 19.34 100797 11.870618 -25.440655 58710.09874 i 20.69 * 159202 19.905190 -12.538276 58710.07075 i 20.92 159202 19.905190 -12.538276 58710.14397 i 20.94 18336 358.741058 -34.601448 58709.95548 g 19.34 * 18336 358.741058 -34.601448 58709.95943 i 18.66 * 6164 357.876587 -34.452286 58709.97820 g 20.98 * 6164 357.876587 -34.452286 58709.98215 i 19.49 * 6164 357.876587 -34.452286 58710.07718 i 17.77 * 6164 357.876587 -34.452286 58710.10239 i 17.37 * 9144 17.207096 -15.948555 58709.99864 i 20.25 9144 17.207096 -15.948555 58710.04417 i 20.90 79197 9.109488 -28.299847 58709.99360 i 20.72 79197 9.109488 -28.299847 58710.13349 i 17.82 37303 16.312994 -19.282728 58710.02899 i 21.57 37303 16.312994 -19.282728 58710.05428 i 20.87 39283 22.277931 -7.641680 58710.03407 i 20.74 39283 22.277931 -7.641680 58710.07714 i 21.20 39283 22.277931 -7.641680 58710.08856 i 21.28 20250 24.165987 -1.395758 58710.12932 i 22.07 20250 24.165987 -1.395758 58710.13858 i 21.25 20250 24.165987 -1.395758 58710.14747 i 22.02 24101 15.515750 -19.450779 58709.95559 g 18.93 24101 15.515750 -19.450779 58709.95952 i 17.93 32325 16.646227 -20.332222 58710.06484 i 20.88 32325 16.646227 -20.332222 58710.07076 i 20.97 116443 18.599520 -15.371491 58710.00371 i 20.32 116443 18.599520 -15.371491 58710.15228 i 21.00 26395 18.458609 -14.845590 58709.96457 g 18.75 26395 18.458609 -14.845590 58709.96852 i 18.08 26395 18.458609 -14.845590 58710.11409 i 21.21 26395 18.458609 -14.845590 58710.13437 i 18.96 26395 18.458609 -14.845590 58710.13488 i 20.80 29956 5.140354 -31.304150 58710.10378 i 18.19 * 29956 5.140354 -31.304150 58710.11845 i 17.58 * 27300 18.368864 -16.241695 58710.03909 i 21.08 27300 18.368864 -16.241695 58710.05922 i 20.78 27300 18.368864 -16.241695 58710.06963 i 20.08 306207 18.245500 -19.008210 58710.06438 i 20.53 306207 18.245500 -19.008210 58710.13963 i 20.56 92141 12.364808 -26.538301 58710.08825 i 20.70 92141 12.364808 -26.538301 58710.09321 i 20.59 35979 19.853939 -15.700216 58709.98634 g 19.93 35979 19.853939 -15.700216 58710.04416 i 20.91 35979 19.853939 -15.700216 58710.11916 i 20.86 9155 17.213064 -15.406333 58709.98635 g 19.89 9155 17.213064 -15.406333 58710.02395 i 20.20 9155 17.213064 -15.406333 58710.03403 i 19.53 32166 22.671516 -3.945191 58709.93742 g 19.80 32166 22.671516 -3.945191 58709.94138 i 19.46 29895 19.050838 -15.909591 58709.93740 g 19.52 29895 19.050838 -15.909591 58709.94138 i 18.18 19844 16.518356 -19.004105 58710.05423 i 20.33 19844 16.518356 -19.004105 58710.10841 i 20.72 19844 16.518356 -19.004105 58710.11411 i 20.95 10265 17.787889 -13.961053 58709.98862 i 19.45 10265 17.787889 -13.961053 58710.00373 i 19.84 20896 13.531107 -21.714043 58710.03418 i 20.11 20896 13.531107 -21.714043 58710.03914 i 20.59 20896 13.531107 -21.714043 58710.34966 i 20.58 18488 13.192388 -22.975018 58709.96471 g 19.16 18488 13.192388 -22.975018 58709.96866 i 18.08 18488 13.192388 -22.975018 58709.99865 i 19.96 18488 13.192388 -22.975018 58710.01384 i 20.34 14661 0.804084 -35.937012 58709.93739 g 18.89 * 14661 0.804084 -35.937012 58709.94134 i 17.84 * 21137 21.162384 -12.635588 58709.94640 g 19.60 21137 21.162384 -12.635588 58709.95037 i 19.98 18105 359.252838 -34.680603 58710.02906 i 20.77 * 18105 359.252838 -34.680603 58710.10719 i 17.49 * 15460 19.836689 -11.868764 58710.01888 i 20.20 15460 19.836689 -11.868764 58710.14253 i 21.17 15460 19.836689 -11.868764 58710.14900 i 20.98 92684 15.547041 -21.241604 58710.04417 i 20.82 92684 15.547041 -21.241604 58710.04922 i 20.71 4791 359.252869 -34.759216 58709.99877 i 20.22 * 4791 359.252869 -34.759216 58710.11229 i 17.10 * 4791 359.252869 -34.759216 58710.11714 i 17.04 * 24481 16.770569 -19.374840 58710.02900 i 20.29 24481 16.770569 -19.374840 58710.12226 i 20.75 35679 21.585737 -7.476670 58710.08355 i 21.80 35679 21.585737 -7.476670 58710.13235 i 21.84 142955 14.254662 -23.837297 58710.00373 i 20.39 142955 14.254662 -23.837297 58710.04924 i 21.43 26992 20.228701 -12.604503 58709.94642 g 19.19 26992 20.228701 -12.604503 58709.95038 i 18.50 16547 15.572316 -19.669104 58710.08011 i 20.81 16547 15.572316 -19.669104 58710.12344 i 20.42 19065 20.243814 -13.850061 58709.98383 g 20.13 19065 20.243814 -13.850061 58709.99359 i 19.01 19065 20.243814 -13.850061 58710.10891 i 18.87 19065 20.243814 -13.850061 58710.10940 i 20.59 35394 19.759592 -14.520414 58710.01380 i 20.17 35394 19.759592 -14.520414 58710.06445 i 20.47 29459 15.488038 -20.901058 58709.98632 g 20.04 29459 15.488038 -20.901058 58710.06964 i 20.47 29459 15.488038 -20.901058 58710.15114 i 16.72 11515 15.674046 -21.882154 58710.00877 i 19.87 11515 15.674046 -21.882154 58710.01376 i 20.01 39192 21.318216 -8.873629 58710.06059 i 20.82 39192 21.318216 -8.873629 58710.11334 i 21.10 38002 20.815937 -9.028175 58710.13353 i 20.61 38002 20.815937 -9.028175 58710.15252 i 21.14 37351 21.584593 -8.088892 58709.96454 g 19.84 37351 21.584593 -8.088892 58709.96855 i 20.01 37351 21.584593 -8.088892 58710.09365 i 22.04 37351 21.584593 -8.088892 58710.12737 i 21.94 27751 12.180364 -23.561686 58710.01887 i 20.83 27751 12.180364 -23.561686 58710.07468 i 20.64 27751 12.180364 -23.561686 58710.14206 i 17.50 92666 16.297606 -20.300508 58710.12843 i 20.33 92666 16.297606 -20.300508 58710.14481 i 20.90 34363 18.214550 -18.130898 58710.10340 i 20.95 34363 18.214550 -18.130898 58710.12423 i 20.81 29371 18.245232 -19.004225 58710.01886 i 20.57 29371 18.245232 -19.004225 58710.02395 i 20.25 18573 19.276611 -13.997672 58709.98861 i 19.85 18573 19.276611 -13.997672 58710.09835 i 21.33 22197 14.285744 -21.919788 58709.95548 g 19.03 22197 14.285744 -21.919788 58709.95943 i 18.08 22197 14.285744 -21.919788 58710.35356 i 19.66 92647 18.175837 -17.343292 58710.10380 i 21.17 92647 18.175837 -17.343292 58710.13744 i 20.99 79373 14.693214 -22.125990 58710.02392 i 20.62 79373 14.693214 -22.125990 58710.08369 i 21.31 567831 23.146976 -33.370922 58710.34656 i 20.05 * 135410 9.096192 -23.016867 58710.28126 i 20.28 33793 24.455557 -32.910164 58710.29624 i 20.07 * 449138 9.530549 -25.067608 58710.30128 i 19.90 532483 13.369438 -21.911320 58710.30631 i 20.34 9027 21.404795 -30.365484 58710.33676 i 19.31 553066 9.248287 -22.514509 58710.31139 i 20.21 2549 17.198074 -28.582380 58710.35156 i 19.82 2549 17.198074 -28.582380 58710.35715 i 19.99 532502 14.722445 -26.997629 58710.33628 i 19.22 532466 12.270871 -22.073545 58710.33960 i 13.89 * 532504 14.967546 -27.683073 58710.34366 i 13.76 * 757122 12.933992 -21.637796 58710.34850 i 19.78 10762 20.811903 -32.841278 58710.35657 i 15.88 * 10762 20.811903 -32.841278 58710.35692 i 19.46 * 10762 20.811903 -32.841278 58710.36184 i 19.74 * 91271 26.489296 -34.819794 58710.31141 i 20.33 * 91271 26.489296 -34.819794 58710.31712 i 20.10 * 92142 9.878608 -25.696756 58710.29116 i 19.73 581757 10.727911 -22.252661 58710.33737 i 18.28 * 581757 10.727911 -22.252661 58710.34459 i 17.22 579526 11.112743 -25.386465 58710.27643 i 19.55 582060 11.917876 -21.603403 58710.32168 i 20.01 20896 13.531107 -21.714043 58710.03418 i 20.11 20896 13.531107 -21.714043 58710.03914 i 20.59 20896 13.531107 -21.714043 58710.34966 i 20.58 9088 16.550928 -30.178104 58710.34181 i 19.62 22613 24.537485 -32.854710 58710.28129 i 19.53 * 448313 9.490071 -25.073734 58710.29117 i 19.81 532499 14.445801 -28.283569 58710.34125 i 19.27 535699 14.955940 -27.687796 58710.28610 i 19.44 2187 9.339670 -19.934246 58710.33859 i 15.37 * 282960 18.447000 -31.747250 58710.28611 i 19.39 * 8020 8.556821 -21.438623 58710.27641 i 20.24 676349 23.601492 -31.605593 58710.32620 i 19.73 * 5952 17.754683 -30.438509 58710.33170 i 19.31 86762 17.037699 -28.523716 58710.30634 i 20.35 79286 12.624772 -21.257549 58710.30132 i 19.73 5789 17.648386 -30.221266 58710.35704 i 17.69 568450 23.327688 -32.893074 58710.31646 i 19.63 * 568450 23.327688 -32.893074 58710.31716 i 20.17 * 19430 19.171112 -31.433949 58710.36196 i 18.01 * 12147 23.839796 -32.776436 58710.34704 i 20.03 * 12147 23.839796 -32.776436 58710.35208 i 20.21 * 22197 14.285744 -21.919788 58709.95548 g 19.03 22197 14.285744 -21.919788 58709.95943 i 18.08 22197 14.285744 -21.919788 58710.35356 i 19.66 98054 13.301269 -21.521597 58710.29621 i 19.63 753269 11.840671 -23.585516 58710.31645 i 19.53 753269 11.840671 -23.585516 58710.32129 i 20.03 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25360 SUBJECT: LIGO/Virgo S190814bv: No candidates identified in DECam data by visual inspection DATE: 19/08/16 09:42:39 GMT FROM: M. Soares-Santos at Fermi Lab Antonella Palmese, Alyssa Garcia, Kathy Vivas, Ken Herner, James Annis, Marcelle Soares-Santos, Douglas Tucker, Sahar Allam, Tristan Bachmann, Alfredo Zenteno On behalf of the DESGW Collaboration*: We report partial results of our counterpart search to the black hole/neutron star merger S190814bv reported by LIGO/VIRGO Collaboration (GCN Circular No. 25324, updated GCN Circular No. 25333). The region was imaged by DECam, on the CTIO Blanco Telescope. First and second epochs were obtained on the nights of 2019 Aug 16 (GCN Circular No. 25336) and Aug 17, at 9.5h and 33h post merger. We observed through clouds and full moon on both nights. Depth achieved is 20.5mag in i and z bands. No candidates were identified on the second epoch data by visual inspection of 524 galaxies nearby galaxies within the 90% 3D localization probability region of the merger. The visual inspection compared the new images with deep pre-existing imaging data obtained by the Dark Energy Survey (DES). 
 Processing using our difference imaging pipeline is ongoing (Herner et al. 2017; see also Soares-Santos et al. 2015, 2017; Doctor et al. 2018; Morgan et al. 2019 for recent applications). The DECam Search & Discovery Program for Optical Signatures of Gravitational Wave Events (DESGW) is carried out by the Dark Energy Survey (DES) collaboration in partnership with wide ranging groups in the community. DESGW uses data obtained with the Dark Energy Camera (DECam), which was constructed by the DES collaboration with support from the Department of Energy and member institutions, and utilizes data as distributed by the Science Data Archive at NOAO. NOAO is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. *DESGW Collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner, (Fermilab), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25361 SUBJECT: LIGO/Virgo S190814bv: GRAWITA TNG infrared imaging of selected galaxies DATE: 19/08/16 10:09:59 GMT FROM: Andrea Rossi at INAF P. D'Avanzo, (INAF-OAB), A. Rossi (INAF-OAS), G. Greco (Urbino Univ.), S. Piranomonte (INAF-OAR), L. Difabrizio, A. Bragaglia, D. Carosati (INAF-TNG), report on behalf of GRAWITA: We observed the position of the 5 galaxies listed below, with the 3.6m Italian TNG telescope (Canary Islands, Spain), equipped with the NICS infrared camera in imaging mode. These targets were selected from the list of probable host galaxies generated by the HOGWARTS code (https://gwtool.watchertelescope.ie/), consistent with the updated 90% probability region of S190814bv (LIGO Scientific Collaboration and Virgo Collaboration, GCN Circ. 25333). Similar lists were coordinated with collaborating telescopes in La Palma and at ESO/VLT. Each galaxy was observed for 20 minutes exposure in the Ks-band filter. Observations were carried out on 2019 Aug 16 between 01:50 and 04:40 UT. Conditions were affected by seeing of ~2 arcseconds. Visual inspection of the 5 fields does not reveal any new candidate compared with archival images from the 2MASS survey. The average upper limit of the images is Ks=19.7 mags (AB system). List of target fields (RA, Dec): ------------------------------- 00:55:09.15 -25:27:20.53 00:48:58.27 -25:41:36.42 00:54:37.67 -25:04:01.56 00:49:53.54 -24:42:25.91 00:50:39.87 -26:48:48.22 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25362 SUBJECT: LIGO/Virgo S190814bv: Candidates identified in DECam images by the DECam-GROWTH team DATE: 19/08/16 11:04:37 GMT FROM: Igor Andreoni at Caltech I. Andreoni (Caltech), D. A. Goldstein (Caltech), T. Ahumada (UMD), S. Anand (Caltech), M. Bulla (OKC), A. Dahiwale (Caltech), K. De (Caltech), S. Dhawan (OKC), M. M. Kasliwal (Caltech), A. K. H. Kong (NTHU), D. Perley (LJMU), Y. Sharma (Caltech), J. Sollerman (OKC), A. Tzanidakis (Caltech), K. Zhang (UCB), S. B. Cenko (NASA GSFC), C. Copperwheat (LJMU), M. W. Coughlin (Caltech), D. Kaplan (UWM) report on behalf of the Global Relay of Observatories Watching Transients Happen (GROWTH) collaboration We processed the public data obtained by the DESGW team (GCN #25336, GCN #25360) during the follow-up of the gravitational wave event S190814bv (GCN #25324) using the image subtraction pipelines described in Goldstein, Andreoni et al. (2019) and Andreoni, Goldstein et al. (2019). Here we report a set of candidates found within the 95% integrated probability area of the LIGO/Virgo LALInference skymap (GCN #25333) that were not previously reported on TNS or via GCN. The candidates are located far from known asteroids present in the Minor Planet Center and were detected at the same location on repeat visits separated by at least 30 minutes. +------------------------------------------- -------------------------------------+ | name | RA | Dec |filter| mag | MJD | notes | +---------------------------------------------------------------------------------+ | DG19hqpgc | 11.736272 | -25.376851 | i | 19.1 | 58710.28 | AT2019npd | (a) | | DG19prsgc | 10.388877 | -23.742207 | z | 20.1 | 58710.28 | AT2019npe | (b)(c)| | DG19frdgc | 11.548253 | -22.118828 | z | 19.9 | 58710.28 | AT2019npj | (d) | | DG19sevhc | 14.050077 | -25.490123 | z | 20.4 | 58711.32 | AT2019npy | (e) | | DG19wgmjc | 13.968328 | -25.783281 | i | 20.5 | 58711.32 | AT2019npw | (e) | | DG19tzyhc | 13.273165 | -24.360753 | z | 20.5 | 58711.25 | AT2019npz | (b) | | DG19qabkc | 22.265283 | -32.705156 | z | 20.8 | 58711.35 | AT2019nqc | (e) | +------------------------------------------ --------------------------------------+ (a) Probably located in the nearby galaxy NGC 0253 (z = 0.00081) therefore unlikely related with S190814bv (b) Consistent with the nucleus of a galaxy, could be AGN. (c) SDSS photo z = 0.1594 +- 0.0225 (d) Hostless, or with a faint counterpart in Pan-STARRS (Chambers et al., 2016) archival images (e) Offset from possible host galaxy The observing conditions on the second night of observations (MJD 58711) were on average better than on the previous night. Therefore, faint candidates identified on the second night may not be 'young' transients close to their onset time. GROWTH is a worldwide collaboration comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, TTU, USyd, Australia, and SDSU, USA. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. We gratefully acknowledge Amazon, Inc. for a generous grant that funded our use of the Amazon Web Services cloud computing infrastructure to process the data above. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25365 SUBJECT: LIGO/Virgo S190814bv: Upper limits from Insight-HXMT/HE observations DATE: 19/08/16 13:07:18 GMT FROM: Ce Cai at IHEP C. Cai, Q. B. Yi, S. Xiao, Q. Luo, C. K. Li, X. B. Li, G. Li, J. Y. Liao, S. L. Xiong, C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, M. Wu, Y. P. Xu, S. N. Zhang (IHEP), report on behalf of the Insight-HXMT team: Insight-HXMT was taking data normally around the reported LIGO/Virgo S190814bv event (GCN #25324), trigger time 2019-08-14T21:10:39.013 UTC. At T0, about 100% of the LIGO localization region was covered by the Insight-HXMT without occultationby the Earth. Within T0 +/- 100 s, no significant excess events (SNR > 3 sigma) are found in a search of the Insight-HXMT/HE raw light curves. Assuming the GW counterpart GRB with three typical GRB Band spectral models, two typical duration timescales (1 s, 10 s) from the center of the LIGO-Virgo location probability map (RA=15 deg, DEC=-20 deg), the 5-sigma upper-limits fluence (0.2 - 5 MeV, incident energy) are reported below: Band model 1 (alpha=-1.9, beta=-3.7, Ep=70 keV): 1 s: 1.2e-07 erg cm^-2 10 s: 8.5e-07 erg cm^-2 Band model 2 (alpha=-1.0, beta=-2.3, Ep=230 keV): 1 s: 1.7e-07 erg cm^-2 10 s: 1.2e-06 erg cm^-2 Band model 3 (alpha=-0.0, beta=-1.5, Ep=1000 keV): 1 s: 3.6e-07 erg cm^-2 10 s: 2.5e-06 erg cm^-2 All measurements above are made with the CsI detectors operating in the regular mode with the energy range of about 80-800 keV (deposited energy). Only gamma-rays with energy greater than about 200 keV can penetrate the spacecraft and leave signals in the CsI detectors installed inside of the spacecraft. Insight-HXMT is the first Chinese space X-ray telescope, which was funded jointly by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). More information could be found at: http://www.hxmt.org. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25366 SUBJECT: LIGO/Virgo S190814bv : No Counterpart Candidates in Galaxy Targeted Search with Magellan DATE: 19/08/16 13:07:29 GMT FROM: Sebastian Gomez at Harvard U S. Gomez, G. Hosseinzadeh, E. Berger, P. K. Blanchard, T. Eftekhari, J. Gill, L. Patton, V. A. Villar, P. K. G. Williams (Harvard U), T. Gardner (U of Michigan), P. S. Cowperthwaite (Carnegie Obs), R. Chornock (Ohio U), W. Fong, R. Margutti (Northwestern U), and M. Nicholl (U Edinburgh) report: We obtained 60s i-band images of the following galaxies from the GLADE catalog (Dalya et al. 2018, MNRAS, 479, 2374) in the LIGO/Virgo localization region of S190814bv (GCN 25324) with the IMACS imager on the Magellan Baade 6.5-m telescope: Shortname R.A. Dec. Date UT 00EQY 00:46:38.0 -24:18:07.0 2019-08-16 09:24:18.2 00HB7 00:53:54.5 -25:23:43.4 2019-08-16 10:19:37.4 00LCX 00:48:13.9 -23:29:35.0 2019-08-16 09:27:10.7 01P3P 00:45:40.8 -24:34:53.6 2019-08-16 10:14:28.9 01P47 00:48:45.3 -23:47:23.4 2019-08-16 10:30:01.7 025PZ 00:46:59.1 -25:22:19.2 2019-08-16 09:15:42.1 02EP7 00:50:42.2 -26:14:39.9 2019-08-16 09:41:26.9 02ESQ 00:49:42.4 -25:54:23.5 2019-08-16 09:12:49.4 02ET0 00:50:40.6 -25:53:07.9 2019-08-16 08:58:20.0 02F2M 00:54:08.0 -24:59:54.3 2019-08-16 09:56:41.9 02F6B 00:49:23.9 -24:38:18.8 2019-08-16 08:37:56.0 02F6F 00:51:45.7 -24:37:48.5 2019-08-16 08:47:00.8 02FGS 00:50:05.2 -23:32:59.8 2019-08-16 10:00:06.7 02UYQ 00:54:39.4 -25:23:13.3 2019-08-16 09:51:01.0 02UYR 00:47:54.9 -25:31:37.4 2019-08-16 09:04:14.4 02WGO 00:52:11.7 -25:39:54.9 2019-08-16 08:40:45.9 02Z2Y 00:48:32.1 -23:44:33.7 2019-08-16 09:01:26.7 03BPH 00:52:35.0 -24:38:08.8 2019-08-16 08:43:55.6 03BPX 00:51:00.2 -24:34:26.5 2019-08-16 08:21:39.0 03BUR 00:48:13.4 -23:42:15.8 2019-08-16 09:18:30.3 04EGS 00:48:25.2 -25:00:02.9 2019-08-16 08:32:12.9 04EGT 00:49:12.0 -24:58:56.4 2019-08-16 08:15:37.9 04EGV 00:50:48.6 -26:16:35.9 2019-08-16 09:47:05.2 04EGW 00:52:34.3 -26:06:07.7 2019-08-16 09:21:19.0 06Q49 00:45:05.5 -24:10:47.5 2019-08-16 10:24:51.4 06Q4B 00:46:37.7 -25:35:31.5 2019-08-16 10:11:35.0 06WM6 00:53:51.2 -25:57:17.2 2019-08-16 10:22:13.5 06WOX 00:47:22.7 -25:46:21.9 2019-08-16 09:53:51.3 06WTE 00:50:22.6 -25:30:30.5 2019-08-16 08:55:27.0 06WTS 00:50:47.9 -25:29:06.7 2019-08-16 08:26:24.7 07KMR 00:52:48.0 -25:07:01.3 2019-08-16 08:35:01.0 07KMZ 00:49:00.8 -25:12:12.5 2019-08-16 08:29:33.4 07KNO 00:47:52.7 -25:31:57.9 2019-08-16 09:07:01.9 07KO9 00:52:55.0 -25:45:29.3 2019-08-16 08:52:35.4 07KOH 00:51:06.7 -25:52:24.8 2019-08-16 08:49:49.6 0BEQ6 00:50:48.8 -26:05:57.8 2019-08-16 09:30:10.4 0BUM7 00:47:52.1 -25:03:29.3 2019-08-16 09:09:53.7 0CED3 00:51:01.5 -26:00:30.7 2019-08-16 10:05:47.4 0P05U 00:48:28.4 -25:37:29.3 2019-08-16 09:44:16.8 0PG1R 00:50:33.5 -25:54:49.5 2019-08-16 10:17:03.2 0PG2E 00:50:45.8 -25:53:32.1 2019-08-16 10:02:58.3 0PG2N 00:50:03.0 -25:53:18.9 2019-08-16 09:33:01.0 0SRXP 00:51:04.1 -26:00:18.6 2019-08-16 09:35:51.5 0SRYJ 00:49:21.1 -25:47:35.6 2019-08-16 09:38:39.9 0SRYS 00:49:03.1 -25:49:43.1 2019-08-16 10:08:42.4 Comparison of the images to the PS1 3pi survey (Chambers et al. 2016, arXiv:1612.05560) reveals no new sources brighter than ~22.2 mag within a 7.6 arcmin field of view. We especially thank Tyler Gardner for taking these observations at Magellan. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25369 SUBJECT: LIGO/Virgo S190814bv: Konus-Wind observations DATE: 19/08/16 15:29:04 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, S. Golenetskii, R.Aptekar, D. Frederiks, M. Ulanov, A. Tsvetkova, A. Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report: Konus-Wind (KW) was observing the whole sky at the time of the LIGO/Virgo event S190814bv (2019-08-14 21:10:39.013 UTC, hereafter T0; LIGO/Virgo Collaboration GCN Circ. 25324). No triggered KW event happened from ~20 hours before and up to ~2 days after T0. The closest waiting-mode event was ~1 hour before T0. Using waiting-mode data within the interval T0 +/- 10 s, we found no significant (> 5 sigma) excess over the background in both KW detectors on temporal scales from 2.944 s to 100 s. We estimate an upper limit (90% conf.) on the 20 - 1500 keV fluence to 5.9x10^-7 erg/cm^2 for a burst lasting less than 2.944 s and having a typical KW short GRB spectrum (an exponentially cut off power law with alpha =-0.5 and Ep=500 keV). For a typical long GRB spectrum (the Band function with alpha=-1, beta=-2.5, and Ep=300 keV), the corresponding limiting peak flux is 1.7x10^-7 erg/cm^2/s (20 - 1500 keV, 2.944 s scale). All the quoted values are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25370 SUBJECT: S190814bv: MASTER analysis of DECam-GROWTH candidates DATE: 19/08/16 15:31:53 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, F.Balakin, E. Gorbovskoy, V. Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V. Vladimirov, D. Vlasenko, I.Gorbunov,D.Zimnukhov, V. Senik, A.Chasovnikov, A.Pozdnyakov,D.Kuvshinov(Lomonosov Moscow State University, SAI, Physics Department), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias IAC), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), H. Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), D. Buckley (South African Astronomical Observatory SAAO), O. Gress, N.M. Budnev, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University) MASTER Global Robotic Net ( http://observ.pereplet.ru, Lipunov et al., 2010,Advances in Astronomy, vol. 2010, 30L) observed S190814bv (LVC GCN 25324) starting 2019-08-14 22:42:29 (Lipunov et al. GCN 25322, GCN25339). We analyzed candidates identified in DECam images by the DECam-GROWTH team (Andreoni et al. GCN25362) in MASTER-Kislovodsk, MASTER-Tavrida, MASTER-SAAO,MASTER-IAC,MASTER-OAFA databases and in VIZIER. 1) 11.736272 -25.376851 There is PanSTARRs optical source in 0.14" with m=20.2(r) and sources in the halo of NGC253 (Bailin+, 2011) http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=&-out.add=_r&-out.add=_RAJ%2C_DEJ&-sort=_r&-to=&-out.max=20&-meta.ucd=2&-meta.foot=1&-c=11.736272+-25.376851&-c.rs=5 MASTER observed this area since 2015-09-15 23:55:17(mlim=20.2), there was no automatically detected sources brighter mlim in history, and now mlim~18 (full Moon in 38deg., 30 deg. obj_altitude). 2) 10.388877 -23.742207 There is OT with unfiltered m=18.2 on 2018-08-10 01:07:54.917UT in MASTER database 3) 11.548253 -22.118828 There is no OT up to 21.4 (2018-11-02 23:59:06UT) in MASTER database, in VIZIER there is WISE AGN candidate (catalogs Assef+, 2018) in 2.9" 4)14.050077 -25.490123 There is optical surce in MASTER images, for ex. (2015-09-15 23:55:17) with unfiltered m~21 (mlim=21.5) there are 2 PanSTARRs sources in 1.4 and 2.1" http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=&-out.add=_r&-out.add=_RAJ%2C_DEJ&-sort=_r&-to=&-out.max=20&-meta.ucd=2&-meta.foot=1&-c=14.050077+-25.490123&-c.rs=5 5)13.968328 -25.783281 There is marginally seen source with m<~mlim=20.0 on 2019-08-15 00:12:22 and m_OT~20.5 on 2015-09-15 23:55:17UT (mlim=21.5) There is USNO-B1 source in 1.2" with R2=21.3, B2=21.0 and PanSTARRs source with r=21.2 6)13.273165 -24.360753 There is a source in our images. MASTER automatic photometry is the following Date_TimeUT unfiltered_m 2019-05-12 03:17:15 19.2 2018-11-03 00:49:21 19.6 2015-01-11 19:31:53 19.2 7)22.265283 -32.705156 There is marginally seen optical source at 2015-09-10 01:36:50Ut (the best summ with mlim=20.8) with m_OT~20.5 in MASTEr database. Also in 2" in VIZIEr database there is a source in USNO-B1, PanSTARR(2.38"), GALEX (3") The observation and reduction of LVC error-box will be continued. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25371 SUBJECT: SUBJECT: LIGO/Virgo S190814bv: GRAWITA VST-ESO PARANAL observations DATE: 19/08/16 16:45:40 GMT FROM: Aniello Grado at INAF-OAC AUTHORS: A. Grado (INAF-Napoli), E. Cappellaro (INAF-Padova), F. Getman (INAF-Napoli), S. Yang (INAF-Padova), E. Brocato (INAF-Abruzzo), P. D'Avanzo (INAF-OABr), S. Covino (INAF-OABr), G. Greco (Universita' Urbino), A. Rossi (INAF-OAS), M. Teresa Botticella (INAF-OACap), L. Izzo (IAA), A. Melandri (INAF-OABr) on behalf of GRAWITA. We observed the field of S190814bv (GCN 25324, GCN 25333) in r' band with the VLT Survey Telescope (VST) equipped with Omegacam (1 sqdeg FOV) (Proposal ID ESO 0103.D-0070 ). In the first night we imaged 18 sqdeg covering 65% of the localization probability region. The observations started on 2019-08-15 at 08:50:26.860 and ended at 10:13:47.602 UT. The seeing was below 2" in thin conditions. In the second epoch we modified the pointings to improve the updated skymap coverage. The area imaged is 23 sqdeg covering 87% of the localization region. The observations started on 2019-08-16 at 05:29:37.904 and ended at 07:20:36.231. The seeing went down to 0.5" in thin conditions. Each 1 sqdeg pointing was observed three times for a total exposure time of 135 seconds. Automatic data processing was done with the VSTTube pipeline (Grado et al. 2012 Mem.SAIt 19, 362). The pointing sequence was generated using the GWsky script ( https://github.com/ggreco77/GWsky). Analysis of the images is in progress. We acknowledge excellent support from the ESO User Support Department and from ESO observing staff in Paranal. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25372 SUBJECT: LIGO/Virgo S190814bv: GROND imaging of candidate galaxies DATE: 19/08/16 18:40:57 GMT FROM: Ting-Wan Chen at MPE T.-W. Chen (MPE), A. Nicuesa Guelbenzu (TLS Tautenburg), M. Fraser (UCD), J. Bolmer (MPE), T. Schweyer (MPE), A. Rau (MPE), S. Klose (TLS Tautenburg), L Salmon (UCD), S. J. Smartt (QUB), A. J. Levan (Radboud Univ), and Paolo D'Avanzo (INAF-OAB) report for a larger collaboration: We observed 36 galaxies within the 90% error volume of S190814bv (LVC GCN 25324) simultaneously in g'r'i'z'JHKs with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile). Observations were obtained on 15 August 2019 between 04:39 and 10:16 UT, 7.5 hours after the GW event. Galaxies were selected from the HOGWARTS code (https://gwtool.watchertelescope.ie/). For each galaxy we obtained on avarage 2.1 min in the optical bands and 3.9 min in the NIR bands. Observations were performed under seeing conditions varying from 1".0 to 2".3 with an average seeing of 1".4, and at an airmass ranging from 1.0 to 1.4 with an average airmass of 1.1. According to these conditions, the typical 3-sigma detection limit in the r' band is 21.3 mag and 19.8 mag in J (all in the AB system). Visual inspection of the r' and J-band images shows no apparent candidates in any of the images in comparison to archival imaging from Pan-STARRS, DSS and WISE. Although we caution that fainter candidates close to their hosts could be missed in such an inspection. The locations of the galaxies observed are --------------------------------------------------- No. RA (J2000) Dec (J2000) 1 10.676272 -21.774082 2 10.242757 -22.083128 3 13.192388 -22.975018 4 11.781363 -24.370647 5 23.594837 -32.835316 6 23.018082 -33.802876 7 12.180364 -23.561686 8 13.806392 -26.321253 9 10.666405 -21.800196 10 23.089487 -31.092321 11 12.364808 -26.538301 12 24.334146 -33.330853 13 14.254662 -23.837297 14 21.229847 -30.621069 15 10.862282 -22.189581 16 13.704722 -26.371256 17 22.342892 -32.849354 18 20.766964 -31.095718 19 11.442945 -25.920193 20 9.807239 -22.102215 21 10.639115 -22.866308 22 23.877426 -32.970612 23 12.25617 -23.811317 24 22.93853 -32.415623 25 12.441799 -26.443037 26 12.120861 -22.147444 27 9.920177 -22.196348 28 11.870618 -25.440655 29 10.91611 -21.659298 30 22.549915 -32.903667 31 11.472051 -23.772461 32 11.543399 -24.650192 33 12.666141 -26.813395 34 12.320091 -26.219179 35 13.804421 -24.044033 36 22.145348 -32.296467 --------------------------------------------------- Note: we re-observed those galaxies (numbers 3, 6, 8, 15, 23 and 29) on 16 August 2019 with GROND, in order to obtain one magnitude deeper images to confirm some possible marginally detected sources taken on 15 August. None of these sources were still detected or convincing though, and we hence do not consider them as genuine sources. We acknowledge excellent help in obtaining these data from Angela Hempel and Régis Lachaume on La Silla. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25373 SUBJECT: LIGO/Virgo S190814bv: New candidates from DECam DESGW difference imaging search DATE: 19/08/16 20:55:58 GMT FROM: Ken Herner at Fermi Nat Accelerator Lab LIGO/Virgo S190814bv: New candidates from DECam DESGW difference imaging search Ken Herner, Antonella Palmese, Marcelle Soares-Santos, Douglas Tucker, Sahar Allam, James Annis, Alyssa Garcia, Robert Morgan, Tristan Bachmann, Dillon Brout On behalf of the DESGW team*: We report 3 new candidate counterparts to the LIGO/Virgo black hole/neutron star merger S190814bv (reported by the LIGO/VIRGO Collaboration in GCN Circular No. 25324, updated GCN Circular No. 25333) found by our target of opportunity program (PI: Soares-Santos, PropID: 2019B-0372), and provide additional photometry on one candidate discovered by GROWTH (PIs: Andreoni & Goldstein, GCN No. 25362). The region was imaged by DECam, on the CTIO Blanco Telescope. First and second epochs were obtained on the nights of 2019 Aug 16 (GCN Circular No. 25336) and Aug 17, at 9.5h and 33h post merger (GCN No. 25360). We observed through clouds and full moon on both nights. Depth achieved is 20.5 mag (10 sigma point source) in i and z bands. Images were processed by our difference imaging pipeline (Herner et al. 2017; see also Soares-Santos et al. 2015, 2017; Doctor et al. 2018; Morgan et al. 2019 for recent applications) using DES images as templates. We employ a machine learning code (autoscan, Goldstein et al. 2015) to reject subtraction artifacts. Candidates were initially selected by requiring at least two high signal to noise detections, rejecting asteroids. We then applied catalog-based vetting to reject variable stars, variable AGNs, using various catalogs including GAIA DR2, and candidates with hosts at redshifts inconsistent (>2sigma, H0=70) with the distance reported by the LVC for S190814bv (276 +/- 56 Mpc) using a variety of photometric and spectroscopic catalogs including DES. The final vetting was done via visual inspection. We matched our remaining candidates using the Transient Name Server to avoid reporting those previously reported by other groups, and the Minor Planet Center to further filter against slow moving asteroids. The following candidates pass our selection criteria: NAME TNS_NAME RA DEC DISCOVERY_MJD DISCOVERY_MAG_I DISCOVERY_MAG_Z desgw-190814c 2019nqq 20.955072 -33.03472 558710.298 20.76 N/A desgw-190814d 2019nqr 23.573539 -32.741781 58711.272 18.34 18.22 desgw-190814e 2019nqs 23.396516 -31.780134 58711.273 20.43 19.69 CANDIDATE_ID HOST_ID HOST_MAG HOST_Z HOST_ZERR ANG_SEP desgw-190814c 2dFGRS TGS507Z156 18.66(R) 0.07 N/A 3.86” desgw-190814d DES-269486823 14.14(i) 0.025 0.01 0.1” desgw-190814e DES- 231522219 17.54(i) 0.139 0.01 1.15” We also detect four (DG19frdgc, DG19tzyhc, DG19prsgc, DG19qabkc) of the candidates previously reported by GROWTH (Goldstein et al., GCN 25362). One of them met our selection criteria: DG19qabkc. We provide additional photometry for their remaining candidate: NAME TNS_NAME RA DEC DISCOVERY_MJD DISCOVERY_MAG_I DISCOVERY_MAG_I_ERR LASTOBS_MJD LASTOBS_MAG_Z LASTOBS_MAG_Z_ERR DG19qabkc AT2019nqc 22.26529 -32.705155 58711.35 21.080 0.014 58711.368 21.283 0.014 All magnitudes reported are observed magnitudes. We encourage spectroscopic followup of these candidates. The DECam Search & Discovery Program for Optical Signatures of Gravitational Wave Events (DESGW) is carried out by the Dark Energy Survey (DES) collaboration in partnership with wide ranging groups in the community. DESGW uses data obtained with the Dark Energy Camera (DECam), which was constructed by the DES collaboration with support from the Department of Energy and member institutions, and utilizes data as distributed by the Science Data Archive at NOAO. NOAO is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. *The DESGW Collboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner, (Fermilab), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25374 SUBJECT: LIGO/Virgo S190814bv: No candidates from DCT galaxy targeted search and observations of DECam-GROWTH candidates DATE: 19/08/16 21:58:42 GMT FROM: Simone Dichiara at UMCP/NASA/GSFC S.Dichiara (UMD, NASA-GSFC), E. Troja (UMD, NASA-GSFC), S.B. Cenko (NASA-GSFC), P. Gatkine (UMD), A. Kutyrev (UMD, NASA-GSFC), J.M. Durbak (UMD), S. Veilleux (UMD), Gabriele Minervini (INAF-IAPS), Roberto Ricci (IRA Bologna) report on behalf of a larger collaboration: We observed LIGO/Virgo S190814bv (Mo et al, GCN Circ. 25324) using the Large Monolithic Imager (LMI) on the 4.3m Discovery Channel Telescope (DCT) at Happy Jack, AZ. Observations started on August 16, 10:06:18 UTC (about 1.54 days after the detection) with SDSS i and r filters. We selected the sample of galaxies from the GLADE v2.3 catalogue (Dalya et al. 2018). We observed 11 galaxies within the 90% error volume of S190814bv obtaining 3x90 sec exposures for each field in i-band and r-band The locations of the galaxies observed are: RA(J2000) DEC (J2000) Filter 00:53:14.256 -25:36:49.68 i,r 00:51:17.208 -25:32:01.32 i,r 00:50:52.416 -25:34:37.56 i,r 00:53:24.864 -25:49:36.48 i,r 00:51:36.648 -25:56:31.92 i 00:51:03.456 -25:58:56.64 i 00:51:15.768 -25:57:39.24 i 00:52:54.792 -26:02:28.68 i 00:52:41.880 -26:04:04.08 i 00:52:59.016 -26:03:03.60 i 00:50:01.104 -26:18:07.20 i Comparing our images against the archival Pan-STARRS images, we do not detect obvious counterparts. Our limiting magnitude is ~22 AB mag in each filter. We also observed some of the candidates reported by Andreoni et al. (GCN Circ. 25362). We detect the sources with the following magnitudes: Name Start Time (UT) Exposure Filter AB Mag ------------------------------------------------------- DG19sevhc 11:15:19 2x60 z' 19.72 +- 0.03 DG19sevhc 11:18:12 2x60 i' 20.13 +- 0.04 DG19qabkc 11:21:39 2x60 z' 20.64 +- 0.09 DG19wgmjc 11:25:09 2x60 i' 20.88 +- 0.07 ------------------------------------------------------- We note that the candidate DG19sevhc has a red color and appears to have brightened by ~0.7 mag in z band. Further observations are planned. We thank the staff of the Discovery Channel Telescope in particular Ishara Nisley for assistance with these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25375 SUBJECT: LIGO/VIRGO S190814bv: No candidates from ATLAS observations DATE: 19/08/17 00:01:01 GMT FROM: Shubham Srivastav at QUB S. Srivastav, S. J. Smartt, K. W. Smith, D. R. Young (QUB), L. Denneau, H. Flewelling, A. Heinze, J. Tonry, H. Weiland (IfA, Univ. Hawaii), A. Rest (STScI), B. Stalder (LSST), C. Stubbs (Harvard), T.-W. Chen (MPE), O. McBrien, M. Dobson, J. Gillanders, D. O'Neil, P. Clark, S. Sim (QUB) We report observations of the LALInference skymap of the NSBH event S190814bv (The LIGO Scientific Collaboration and the Virgo Collaboration, GCN 25324, 25333) with the ATLAS telescope system (Tonry et al. 2018, PASP, 13, 164505). ATLAS is a twin 0.5m telescope system on Haleakala and Mauna Loa employing two filters - cyan and orange. While carrying out the primary mission for Near Earth Objects, we can adjust the schedule rapidly to point at LVC gravitational wave skymaps. The survey provides coverage from declination -40 to +80 every 2 nights to typical depths of 19.5 mag in the o-band. S190814bv was discovered at MJD 58709.88239579 (GCN 25324). ATLAS was observing the whole (99.8% enclosed probability) of the LALInference skymap a few hours before the GW event (and 2 days previously on MJD 58707). The last image of the field, at the end of the night was taken on MJD 58709.63026325 (~6 hrs before S190814bv - see McBrien et al. GCN 25346). We observed the field again on the two subsequent nights on MJDs ~58710.5 and ~58711.5. Sequences of 30 sec images were taken in the ATLAS o/c bands, and at each pointing position a sequence of quads (4 x 30 sec) was taken. The images were processed with the ATLAS pipeline and reference images subtracted from each one. Transient candidates were run through our standard filtering procedures, combined with machine learning algorithms (e.g. Wright et al. 2015, MNRAS, 449, 451). Candidates were spatially cross-matched with known minor planets, and star, galaxy, AGN and multi-wavelength catalogues (as described in Smartt et al. 2016, MNRAS, 462 4094; Stalder et al. 2017, ApJ, 850, 149). No new candidates were found on any of the 3 nights, either ~6 hrs before the GW event, or ~16 hrs and ~40 hrs later, to limiting magnitudes of o ~ 19.0. This work has made use of data from the Asteroid Terrestrial-impact Last Alert System (ATLAS) project. ATLAS is primarily funded to search for near earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; byproducts of the NEO search include images and catalogs from the survey area. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen's University Belfast, and the Space Telescope Science Institute. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25376 SUBJECT: LIGO/Virgo S190814bv: no candidates from optical imaging of selected galaxies at the NOT DATE: 19/08/17 00:32:54 GMT FROM: Daniele B Malesani at DTU Space Kasper E. Heintz (Univ. Iceland), Daniele B. Malesani (DTU Space), Giorgos Leloudas (DTU Space), Darach J. Watson (DAWN/NBI), Jens Hjorth (DARK/NBI), Silvia Piranomonte (INAF/OAR), Nicholas E. Jannsen (NOT), report on behalf of a larger collaboration: We observed the position of the 10 galaxies listed below, using the Nordic Optical Telescope equipped with the ALFOSC instrument. These targets were selected from the list of most probable host galaxies generated by the HOGWARTS code (https://gwtool.watchertelescope.ie/), consistent with the latest available 90% probability region of S190814bv (LIGO Scientific Collaboration and Virgo Collaboration, GCN 25333). Each galaxy was observed for 5 minutes using the SDSS i filter. Observations started around 2019 August 16.15 UT (1.27 days after the GW event) and lasted about 1.5 hr. Conditions were unfortunately affected by the nearby bright Moon and the poor seeing (1.6-2.5") leading to shallower than expected images. Visual inspection of the galaxies does not reveal any new candidate compared to the deeper archival images from the Pan-STARRS survey. The typical limiting magnitude is i ~ 19.5 AB (3 sigma), but we caution that the actual limit is shallower at locations superimposed on the brightest parts of the targeted galaxies. This limit corresponds to an absolute magnitude M_i > -17.5 at a distance of 276 Mpc, which would not have allowed us to detect an event as bright as AT 2017gfo. List of targeted fields (RA, Dec, name) 00:47:07.527 -24:22:14.33 ESO474-026 00:48:43.287 -23:33:42.07 IC1587 00:48:21.859 -25:07:36.53 00:49:01.481 -23:48:40.74 00:52:41.582 -25:44:01.87 ESO474-035 00:47:28.948 -25:26:26.36 00:55:13.534 -26:19:16.51 00:46:10.416 -24:39:00.69 00:49:27.554 -26:32:17.88 00:51:29.863 -24:38:32.98 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25377 SUBJECT: LIGO/Virgo S190814bv: No candidates found in J-GEM follow-up observations DATE: 19/08/17 00:36:41 GMT FROM: Yousuke Utsumi at Hiroshima Astrophys. Science Center Nakaoka, T.; Sasada, M. (Hiroshima U.); Adachi, R.; Yatsu, Y.; Murata, K. L. (Tokyo Tech.); Yanagisawa, K.; Yoshida, M. (NAOJ); Onozato, H. (Nishi-Harima Astronomical Observatory); Tanaka, M. (Tohoku U.); Morokuma, T (U. Tokyo); Utsumi, Y. (Stanford/SLAC) on behalf of J-GEM collaboration We report galaxy-targeted observations for the gravitational wave event S190814bv (Mo et al, GCN Circ. 25324). We started our observations from 2019-08-16 15:21 UT about 1.7 days after the event and ended at 2019-08-16 19:12 UT. We performed galaxy-targeted observations for 31 galaxies (see the table below) selected from the GLADE catalog (Dalya et al. 2018) in the probability skymap of S190814bv using the following telescopes and instruments. We found no apparent transient objects in these galaxies to 5 sigma limiting magnitudes in AB listed below. galid ra dec G R I J H obsid --------------- ------- -------- ---- ---- ---- ---- ---- ------------- GL004822-250737 12.0911 -25.1268 -- 19.3 -- -- 19.1 Kanata-HONIR GL005130-243833 12.8744 -24.6425 14.7 12.9 13.7 -- -- MITSuME-Akeno GL005242-254402 13.1733 -25.7339 -- 18.3 -- -- 18.8 Kanata-HONIR GL004843-234623 12.1782 -23.7731 -- 19.0 -- -- 19.6 Kanata-HONIR GL005010-231648 12.5404 -23.28 -- -- -- 16.5 -- OAOWFC GL005033-231744 12.6379 -23.2955 -- -- -- 16.5 -- OAOWFC GL004915-235131 12.3111 -23.8585 -- 19.0 -- -- 19.6 Kanata-HONIR GL004917-261309 12.3201 -26.2192 -- -- -- 18.1 -- OAOWFC GL005215-244155 13.064 -24.6987 14.7 12.9 13.7 -- -- MITSuME-Akeno GL005033-230100 12.6392 -23.0166 -- -- -- 16.5 -- OAOWFC GL004058-220500 10.2428 -22.0831 -- 18.4 -- -- 19.1 Kanata-HONIR GL005115-231730 12.811 -23.2916 -- -- -- 16.5 -- OAOWFC GL004923-263027 12.3463 -26.5075 -- -- -- 18.1 -- OAOWFC GL004933-263219 12.3856 -26.5386 -- -- -- 18.1 -- OAOWFC GL005045-232020 12.6863 -23.3388 -- -- -- 16.5 -- OAOWFC GL005247-254018 13.1945 -25.6716 -- 18.3 -- -- 18.8 Kanata-HONIR GL004920-262835 12.332 -26.4764 -- -- -- 18.1 -- OAOWFC GL005116-231740 12.8152 -23.2944 -- -- -- 16.5 -- OAOWFC GL004934-263624 12.3936 -26.6067 -- -- -- 18.1 -- OAOWFC GL004918-262834 12.3237 -26.4761 -- -- -- 18.1 -- OAOWFC GL004708-242214 11.7814 -24.3706 -- 18.0 -- -- 18.5 Kanata-HONIR GL004922-261533 12.3437 -26.2592 -- -- -- 18.1 -- OAOWFC GL004934-261716 12.3924 -26.2878 -- -- -- 18.1 -- OAOWFC GL004843-233342 12.1804 -23.5617 -- 19.3 -- -- 20.1 Kanata-HONIR GL004729-252626 11.8706 -25.4407 -- 19.3 -- -- 18.5 Kanata-HONIR GL004928-263218 12.3648 -26.5383 -- -- -- 18.1 -- OAOWFC GL005001-261807 12.5046 -26.302 -- -- -- 18.1 -- OAOWFC GL004914-263121 12.3096 -26.5224 -- -- -- 18.1 -- OAOWFC GL004946-262635 12.4418 -26.443 -- -- -- 18.1 -- OAOWFC GL004901-234841 12.2562 -23.8113 -- 19.0 -- -- 19.6 Kanata-HONIR GL005424-252751 13.6014 -25.4641 -- 17.6 -- -- 19.1 Kanata-HONIR Kanata-HONIR: 150 cm Kanata telescope at Higashi-Hiroshima Observatory and HONIR -- a 2 channel imager (Rc and H) (Akitaya et al. 2014, Proc. SPIE 9147, 91474O) MITSuME-Akeno: 50 cm MITSuME telescope at Akeno Observatory and a 3 color imager (g, Rc, Ic) OAOWFC: 91 cm Okayama Astrophysical Observatory NIR Wide Field Camera, OAOWFC (J) (Yanagisawa, K., et al. 2016, Proc. SPIE, 9908, 99085D) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25379 SUBJECT: LIGO/Virgo S190814bv: SOAR spectroscopy of 2 DESGW candidates DATE: 19/08/17 07:38:57 GMT FROM: Douglas Tucker at Fermilab LIGO/Virgo S190814bv: SOAR spectroscopy of 2 DESGW candidates Douglas Tucker, Sahar Allam, Matthew Wiesner, Regis Cartier, Alyssa Garcia, Antonella Palmese, Alfredo Zenteno, Ken Herner, Marcelle Soares-Santos, James Annis, Tristan Bachman, Martin Makler, Nora Sherman, Luidhy Santana, Charlie Kilpatrick, Andre Luiz Fiigueiredo, Jhon Joel Yana Galar, Juan Espinoza On behalf of the DESGW team*: We report SOAR Goodman spectroscopy of AT2019nqq and AT2019nqr, two candidate counterparts to the black hole-neutron star merger S190814bv (LVC, GCN Circulars No. 25324 and 25333). These candidates were found by the DESGW teams on CTIO Blanco DECam data (GCN Circular No. 25373). Our initial analysis results include: AT2019nqq (desgw-190814c): broad emission line at 7000 angstroms, inconclusive whether continuum is consistent with black-body like spectrum (further analysis is ongoing). AT2019nqr (desgw-190814d): consistent with a Type IIb SN on a Seyfert Type 2 host galaxy. The SOAR followup program is a partnership between the US (PIs: Tucker & Kilpatrick), Chilean (PI: Olivares), and Brazilian (PI: Makler) community. The optical counterpart was identified by the DECam Search & Discovery Program for Optical Signatures of Gravitational Wave Events (DESGW, PI: Soares-Santos), which is carried out by the Dark Energy Survey (DES) collaboration in partnership with wide ranging groups in the community. DESGW uses data obtained with the Dark Energy Camera (DECam), which was constructed by the DES collaboration with support from the Department of Energy and member institutions, and utilizes data as distributed by the Science Data Archive at NOAO. NOAO is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, Inovações e Comunicações do Brasil (MCTIC/LNA), the U.S. National Science Foundation's National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). *The DESGW Collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner, (Fermilab), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25381 SUBJECT: LIGO/Virgo S190814bv: No additional candidates from the Zwicky Transient Facility DATE: 19/08/17 10:13:34 GMT FROM: Robert Stein at DESY Leo P. Singer (NASA GSFC), Mansi M. Kasliwal (Caltech), Michael W. Coughlin (Caltech), Anna Franckowiak (DESY), Robert Stein (DESY), Jannis Necker (DESY), Jesper Sollerman (OKC), Ariel Goobar (OKC), Shreya Anand (Caltech), Tomas Ahumada (UMD), Eric Bellm (UW), Igor Andreoni (Caltech), Dmitry Duev (Caltech), Kishalay De (Caltech), Matt Hankins (Caltech), Danny Goldstein (Caltech), Samaya Nissanke (UofA), Harsh Kumar (IITB), Varun Bhalerao (IITB), Joshua S. Bloom (UCB), David Kaplan (UWM), Daniel A. Perley (LJMU), S. Bradley Cenko (NASA) report on behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations: We again observed the localization region of the gravitational wave trigger S190814bv (GCN 25324, GCN 25333) with the Palomar 48-inch telescope equipped with the 47 square degree ZTF camera (Bellm et al. 2019, Graham et al. 2019, GCN 25343). The tiling was optimally determined and triggered using the GROWTH Target of Opportunity marshal (Coughlin et al. 2019a, Kasliwal et al. 2019b). We started obtaining target-of-opportunity observations in the g-band, r-band and i-band filters beginning at UT 2019-08-16 10:48 UT. We covered 86% of the enclosed probability before 12-deg twilight and analyzed in real-time. Each exposure was 300s with a typical depth of ~20.0 mag due to the high airmass. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). AMPEL (Nordin et al. 2019) was used to vet candidates based on their light curves. After rejecting stellar sources (Tachibana and Miller 2018) and moving objects and applying machine learning algorithms (Mahabal et al. 2019), and after removing candidates with history of variability prior to the merger time, no new transient candidates were identified by our pipeline in the 90% localization. ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, TTU, and USyd, Australia. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert filtering and follow-up co-ordination is being undertaken by the GROWTH marshal system (Kasliwal et al. 2019). [GCN OPS NOTE(24aug19): Per author's request, in the SUBJECT line, "S190425bv" was changed to "S190814bv".] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25382 SUBJECT: LIGO/Virgo S190814bv : No Counterpart Candidates in Continued Galaxy Targeted Search with Magellan DATE: 19/08/17 10:45:12 GMT FROM: Sebastian Gomez at Harvard U S. Gomez, G. Hosseinzadeh, E. Berger, P. K. Blanchard, T. Eftekhari, J. Gill, L. Patton, V. A. Villar, P. K. G. Williams (Harvard U), T. Gardner (U of Michigan), P. S. Cowperthwaite (Carnegie Obs), R. Chornock (Ohio U), W. Fong, R. Margutti (Northwestern U), and M. Nicholl (U Edinburgh) report: We continued observations first reported in GCN 25366. We obtained 60s i-band images of the following galaxies from the GLADE catalog (Dalya et al. 2018, MNRAS, 479, 2374) in the LIGO/Virgo localization region of S190814bv (GCN 25324) with the IMACS imager on the Magellan Baade 6.5-m telescope: Shortname R.A. Dec. Date UT 00O78 00:54:43.5 -26:15:09.4 2019-08-17 09:39:06.3 00Q1K 00:54:43.6 -23:58:31.5 2019-08-17 10:11:31.6 01P3X 00:46:59.0 -22:57:15.8 2019-08-17 10:08:54.2 O1P47 00:48:45.2 -23:47:24.1 2019-08-17 08:13:23.8 01P4L 00:50:44.0 -26:23:32.7 2019-08-17 09:25:56.0 01P52 00:52:05.8 -26:40:56.3 2019-08-17 09:41:40.8 01P5C 00:52:41.9 -26:01:31.5 2019-08-17 08:24:10.3 01PFS 00:54:19.1 -26:18:09.2 2019-08-17 08:48:28.4 01Z17 00:53:25.0 -24:00:30.3 2019-08-17 09:20:51.3 01Z18 00:45:23.9 -23:42:14.0 2019-08-17 09:07:27.0 01Z1I 00:49:16.0 -26:22:27.7 2019-08-17 08:21:31.2 01Z1J 00:48:57.5 -26:28:10.8 2019-08-17 09:10:05.3 O2097 00:48:49.6 -26:24:27.8 2019-08-17 08:38:17.0 025Q2 00:49:40.4 -23:12:41.1 2019-08-17 08:59:23.5 025QB 00:44:33.9 -24:57:04.0 2019-08-17 09:36:32.4 02RYZ 00:54:42.8 -26:15:44.2 2019-08-17 09:02:22.6 02UYV 00:48:32.9 -26:33:00.1 2019-08-17 09:15:44.3 02WGH 00:50:28.3 -23:29:22.0 2019-08-17 08:16:19.3 034FY 00:50:03.8 -23:13:36.4 2019-08-17 09:12:46.7 O3BG6 00:52:56.0 -26:31:52.2 2019-08-17 08:43:22.7 03BPO 00:44:32.4 -24:36:47.6 2019-08-17 08:51:02.6 03BU1 00:54:14.0 -23:48:31.4 2019-08-17 09:46:59.3 03BU6 00:44:34.6 -23:46:55.6 2019-08-17 10:00:56.4 03BX8 00:50:15.4 -23:16:12.7 2019-08-17 09:23:21.8 03BZH 00:46:23.7 -22:57:53.2 2019-08-17 09:33:46.2 042ZA 00:45:23.8 -23:42:42.7 2019-08-17 09:18:16.2 06WD0 00:50:10.6 -26:36:29.4 2019-08-17 08:53:41.4 06WGS 00:54:23.4 -26:18:45.2 2019-08-17 09:04:53.2 06WGY 00:50:50.5 -26:18:08.8 2019-08-17 08:29:18.0 06WHY 00:55:38.8 -26:13:21.1 2019-08-17 10:27:14.3 06X0M 00:55:37.0 -24:58:01.3 2019-08-17 09:58:20.0 07KOT 00:45:47.3 -25:45:19.3 2019-08-17 09:28:35.9 0BUME 00:48:53.1 -26:26:19.8 2019-08-17 09:31:11.0 0BUMG 00:49:02.5 -26:28:11.7 2019-08-17 09:49:39.1 0CE0N 00:50:08.9 -26:20:16.1 2019-08-17 10:03:29.2 0CEW6 00:45:19.8 -25:27:10.5 2019-08-17 10:14:31.6 OCFN6 00:53:28.2 -24:28:28.3 2019-08-17 08:35:44.3 0CFU7 00:46:35.7 -24:10:12.4 2019-08-17 08:18:56.4 0G51H 00:50:25.1 -23:33:47.8 2019-08-17 10:06:19.0 0PFOO 00:51:52.3 -26:15:37.6 2019-08-17 08:45:57.6 0PFR3 00:48:52.5 -26:11:25.8 2019-08-17 10:22:07.0 0PFY3 00:52:11.9 -25:59:57.3 2019-08-17 08:31:50.0 0PG2Y 00:49:22.3 -25:52:39.0 2019-08-17 08:26:42.2 0PG6Z 00:47:12.7 -25:46:08.2 2019-08-17 09:52:11.7 0PGRC 00:45:40.7 -25:08:40.6 2019-08-17 10:19:36.1 OSRQ0 00:50:47.4 -25:27:54.1 2019-08-17 08:40:49.6 0SRQ6 00:49:53.9 -25:34:51.5 2019-08-17 09:44:24.8 0SRQL 00:45:22.2 -25:24:57.5 2019-08-17 10:17:03.6 OSRWW 00:52:29.1 -25:58:56.9 2019-08-17 08:08:38.9 0SRYR 00:49:04.2 -26:13:09.0 2019-08-17 09:55:03.3 0SRZB 00:48:16.0 -25:53:51.1 2019-08-17 08:56:18.6 Comparison of the images to the PS1 3pi survey (Chambers et al. 2016, arXiv:1612.05560) reveals no new sources brighter than ~22.0 mag within a 7.6 arcmin field of view. We especially thank Tyler Gardner for taking these observations at Magellan. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25383 SUBJECT: LIGO/Virgo S190814bv: GRAWITA TNG infrared imaging of desgw-190814e, DG19sevhc and selected galaxies DATE: 19/08/17 13:31:37 GMT FROM: Paolo D'Avanzo at INAF-OAB A. Rossi (INAF-OAS), P. D'Avanzo, (INAF-OAB), E. Cappellaro (INAF-OAPD), M. T. Botticella (INAF-OA Capodimonte), A. Giunta (ASI/SSDC, INAF-OAR), G. Greco (Urbino Univ.), S. Piranomonte (INAF-OAR), A. Harutyunyan, A. Magazzu’, G. Mainella (INAF-TNG), report on behalf of GRAWITA: We observed the targets listed below, within with the updated 90% probability region of S190814bv (LIGO Scientific Collaboration and Virgo Collaboration, GCN Circ. 25333), with the 3.6m Italian TNG telescope (Canary Islands, Spain), equipped with the NICS infrared camera in imaging mode. Observations were carried out on 2019 Aug 17 between 03:53 and 05:04 UT. Conditions were affected by clouds. ID RA, Dec: -------------------------------------------------- desgw-190814e/AT2019nqs 01:33:35.16 -31:46:48.48 DG19sevhc/AT2019npy 01:33:35.16 -31:46:48.48 ESO474-026 00:47:07.53 -24:22:14.33 The first two targets were reported as possible candidate counterparts of S190814bv (Andreoni et al., GCN Circ. 25362; Herner et al., GCN Circ 25373; Dichiara et al., GCN Circ 25374). We observed these two targets with the J filter, with an exposure of 20 minutes per target. We do not detect desgw-190814e/AT2019nqs, likely because the source has a very small offset from its host galaxy center. We can barely detect DG19sevhc/AT2019npy. After image subtraction with a template image from the 2MASS catalogue we obtain for DG19sevhc/AT2019npy a marginal detection with magnitude J = 18.3 +/- 0.3 (AB; obtained with PSF photometry). The galaxy ESO474-026 was observed with the Ks filter, with an exposure of 20 minutes. Visual inspection does not reveal any new candidate. The average 3sigma upper limits of our images are J ~ 20.5 (AB) and Ks ~ 20 (AB), calibrated against the 2MASS catalogue. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25384 SUBJECT: LIGO/Virgo S190814bv : ENGRAVE X-shooter spectra of AT2019nqs and AT2019npy DATE: 19/08/17 16:58:21 GMT FROM: Andrew Levan at U.of Leicester S. H. Bruun (DARK/NBI), A. Sagues Carracedo (OKC), T.-W. Chen (MPE), C. Copperwheat (LJMU), P. D'Avanzo (INAF), M. Fraser (UCD), K. E. Heintz (U. Iceland), J. Hjorth (DARK/NBI), J. Japelj (API, Amsterdam), P. Jonker (SRON/Radboud Univ.), G. Leloudas (DTU Space), A. J. Levan (Radboud Univ), D. B. Malesani (DTU Space), I. Mandel (Monash), D. A. Perley (LJMU), N. B. Sabha (Univ. Innsbruck), S. Schulze (Weizmann), S. Smartt (QUB), J. Sollerman (OKC), D. Steeghs (Warwick), S. D. Vergani (Paris Observatory-CNRS) report on behalf of the ENGRAVE collaboration: We obtained spectroscopy of transients located within the error region of S190814bv (LVC GCN 25333). Observations were taken of desgw-190814e (AT2019nqs: Herner et al., GCN 25373; Dichiara et al., GCN 25374) and DESsevhc (AT2019npy; Andreoni et al., GCN 25362) with the VLT equipped with X-shooter on 17 August 2019. The spectrum of desgw-190814e (AT2019nqs) exhibits clear emission lines of H-alpha and [N II] at a redshift of z = 0.1263 +/- 0.001. The continuum contains significant host galaxy contamination, but is consistent with an old type Ia or Ibc supernova (around 20-50 days post-maximum) whose sub-type cannot be reliably determined. This classification was determined using DASH (Muthukrishna et al. 2019), redshift of 0.126, and adding host contamination (Sa-type spectrum at roughly 60%). More refined classification will require further work. This redshift corresponds to a distance of almost 600 Mpc and lies >6 sigma from the inferred GW distance. We therefore conclude that desgw-190814e is not associated with S190814bv. No discrete features are readily identified in the noisy spectrum of DESsevhc (AT2019npy). The source exhibits a red continuum but no obvious broad lines from a transient or narrow emission lines from a host galaxy. The source does not appear spectrally similar to AT2017gfo. We thank the staff at Paranal for their excellent assistance with these observations. Based on observations collected by the ENGRAVE collaboration at the European Southern Observatory under ESO programmes 1102.D-0353, 0103.D-0703, 0103.D-0722 (for further information on ENGRAVE see http://www.engrave-eso.org/). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25385 SUBJECT: LIGO/Virgo S190814bv: Fermi-LAT search for a high-energy gamma-ray counterpart DATE: 19/08/17 18:56:37 GMT FROM: Masanori Ohno at Hiroshima University M. Ohno (Hiroshima Univ.), M. Axelsson (KTH and Stockholm Univ.), F. Longo (Univ. and INFN Trieste), D. Kocevski (NASA/MSFC), N. Omodei (Stanford Univ.) and F. Dirirsa (Univ. of Johannesburg) report on behalf of the Fermi-LAT Collaboration: We have searched data collected by the Fermi Large Area Telescope (LAT) on Aug 14, 2019, for possible high-energy (E > 100 MeV) gamma-ray emission in spatial/temporal coincidence with the LIGO/Virgo trigger S190814bv (GCN 25324). We define "instantaneous coverage" as the integral over the region of the LIGO probability map that is within the LAT field of view at a given a time, and "cumulative coverage" as the integral of the instantaneous coverage over time. Fermi-LAT had instantaneous coverage of the full LIGO probability region at the time of the trigger (T0 = 2019-08-14 21:10:39.013 UTC). We performed a search for a transient counterpart within the observed region of the 90% contour of the LIGO map in a fixed time window from T0 to T0 + 10 ks. No significant sources were found. We also performed a search which adapted the time interval of the analysis to the exposure of each region of the sky, and no additional excesses were found. Energy flux upper bounds for the fixed time interval between 100 MeV and 1 GeV for this search vary between 3.1e-10 and 8.5e-10 [erg/cm^2/s]. The Fermi-LAT point of contact for this event is Feraol Dirirsa ( fdirirsa@uj.ac.za). The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25386 SUBJECT: LIGO/Virgo S190814bv: Pan-STARRS imaging indicates DG19sevhc (AT2019npy) is a proper motion star DATE: 19/08/17 22:45:05 GMT FROM: Stephen Smartt at Queen's U/Belfast S. Smartt (QUB), D. Malesani (DARK), K. W. Smith (QUB), M. Huber (IfA, Univ. of Hawaii), K. Chambers, A. Schulz (IfA), D. R. Young, O. McBrien, J. Gillanders. S. Srivastav, D. O'Neil, P. Clark, S. Sim (QUB), T. de Boer, J. Bulger, J. Fairlamb, M. Huber, C.-C. Lin, T. Lowe, E. Magnier, R. J. Wainscoat, M. Willman (IfA, Univ. of Hawaii), T.-W, Chen (MPE), A. Rest (STScI), C. Stubbs (Harvard) In the search of the skymap of the NSBH event S190814bv (The LIGO Scientific Collaboration and the Virgo Collaboration, GCN 25333, 25324) the DECam-GROWTH team identified DG19sevhc (AT2019npy; Andreoni et al. GCN 25362) as a candidate. It was followed up by Rossi et al (GCN 25383) and Dichiara et al. (GCN 25374). The latter reported an unusual and rapid z-band rise, which drew attention. We found a previous source detection close to this position on difference images taken during the Pan-STARRS Survey For Transients (Huber et al. 2015, ATel 7153) at i=20.9, on multiple images from MJD=58335 (2018-08-05). However closer inspection revealed that the source was not a transient. There is a faint red star which is coincident with background extended flux (probably a faint, red galaxy) and the star appears to have slow proper motion. This produced a dipole source in the Pan-STARRS difference images, and triggered a new source detection. The motion between the Pan-STARRS reference and the image from MJD=58335 is visually clear (about 1.4 arcsec). We further inspected the separate Pan-STARRS 3Pi epochs (Chambers et al. 2016, arXiv:1612.05560C). Using 3 images with reasonable S/N between 2010 September and 2014 August, plus the public DECam image from 2019 August, the position of the star traces a vector towards the S-E. We estimate a proper motion of 0.07 and -0.12 arcsec/yr in RA and Dec, respectively. Hence we conclude that AT2019npy is not a transient, but resulted from the proper motion of this star leaving a positive residual in the DECam images of 2019 August, and the DECam references. The unusual spatial coincidence of the moving star and background galaxy made the original DECam identification as a transient quite understandable and reasonable. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25389 SUBJECT: LIGO/Virgo S190814bv: No candidates found in J-GEM follow-up observations DATE: 19/08/18 03:07:50 GMT FROM: Mahito Sasada at Hiroshima University Shikauchi, M. (U. Tokyo); Tanaka, M. (Tohoku U.); Kamei, Y.; Fujii H.; Tristram P.; Abe F. (Nagoya U.); Tanaka Y. (Osaka U.); Nakaoka, T.; Sasada, M. (Hiroshima U.); Yanagisawa, K.; Yoshida, M. (NAOJ); Takarada, T. (Saitama U.); Onozato, H. (U. Hyogo); Murata, K. L. (Tokyo Tech.); Itoh, R. (Bisei Astronomical observatory); Utsumi, Y. (Stanford/SLAC) on behalf of J-GEM collaboration We report imaging observations for the gravitational wave event S190814bv (Mo et al, GCN Circ. 25324). We began our first set of observations and reported in Nakaoka et al., GCN Circ. 25377. This report is the second set of observations from 2019-08-17 14:05 UT about 2.7 days after the event and ended at 2019-08-17 18:32 UT. We performed galaxy-targeted observations for 23 galaxies (see the table below) selected from the GLADE catalog (Dalya et al. 2018) in the probability skymap of S190814bv using the following telescopes and instruments. We found no apparent transient objects in these galaxies to 5 sigma limiting magnitudes in the AB system listed below. galid ra dec g r R i z J H obsid --------------- -------- -------- ---- ---- ---- ---- ---- ---- ---- -------------------------- GL004822-250737 12.0911 -25.1268 18.9 19.4 19.3 18.7 -- -- 19.1 BandC-Tripol GL005130-243833 12.8744 -24.6425 99.9 99.9 12.9 99.9 -- -- -- BandC-Tripol GL005242-254402 13.1733 -25.7339 99.9 99.9 18.3 99.9 -- -- 18.9 BandC-Tripol,Kanata-HONIR GL004705-241419 11.7719 -24.2387 13.6 19.2 -- 18.3 99.9 -- -- SaCRA-MuSaSHI,BandC-Tripol GL005111-255715 12.7938 -25.9542 19.3 19.5 -- 18.8 -- -- -- BandC-Tripol GL005119-261005 12.8282 -26.1681 19.3 15.0 -- 13.2 -- -- -- BandC-Tripol GL004242-214627 10.6763 -21.7741 -- -- 17.5 -- -- -- 17.3 Kanata-HONIR GL004915-235131 12.3111 -23.8585 99.9 99.9 19.0 99.9 -- -- 19.6 BandC-Tripol GL004858-254136 12.2428 -25.6934 19.3 19.3 -- 18.8 -- -- -- BandC-Tripol GL004855-250410 12.229 -25.0695 19.4 19.6 -- 18.3 -- -- -- BandC-Tripol GL004923-263027 12.3463 -26.5075 19.6 19.4 -- 18.2 -- 18.1 -- BandC-Tripol GL004933-263219 12.3856 -26.5386 19.6 19.4 -- 18.2 -- 18.1 -- BandC-Tripol GL235701-344533 359.2529 -34.7592 -- -- 18.9 -- -- -- 18.9 Kanata-HONIR GL005247-254018 13.1945 -25.6716 -- -- 18.3 -- -- -- 18.9 Kanata-HONIR GL004240-214801 10.6664 -21.8002 -- -- 17.5 -- -- -- 17.3 Kanata-HONIR GL005116-255739 12.8157 -25.9609 19.3 19.5 -- 18.8 -- -- -- BandC-Tripol GL005103-255857 12.7644 -25.9824 19.3 19.5 -- 18.8 -- -- -- BandC-Tripol GL012733-044059 21.8892 -4.6829 -- -- 19.4 -- -- -- 18.6 Kanata-HONIR GL004610-251248 11.5434 -25.2132 -- -- -- -- -- 18.0 -- OAOWFC GL013640-012345 24.166 -1.3958 -- -- 17.4 -- -- -- 16.9 Kanata-HONIR GL004729-252626 11.8706 -25.4407 99.9 99.9 19.3 16.9 -- 18.0 18.5 BandC-Tripol,OAOWFC GL004928-263218 12.3648 -26.5383 19.6 19.4 -- 18.2 -- 18.1 -- BandC-Tripol GL235701-344050 359.2528 -34.6806 -- -- 18.9 -- -- -- 18.9 Kanata-HONIR BandC-Tripol: 61 cm Boller & Chivens telescope at Mt. John Observatory in New Zealand (B&C) and a three color imager Tripole5 (g, r, i) Kanata-HONIR: 150 cm Kanata telescope at Higashi-Hiroshima Observatory and HONIR -- a 2 channel imager (Rc and H or J) (Akitaya et al. 2014, Proc. SPIE 9147, 91474O) OAOWFC: 91 cm Okayama Astrophysical Observatory NIR Wide Field Camera, OAOWFC (J) (Yanagisawa, K., et al. 2016, Proc. SPIE, 9908, 99085D) SaCRA-MuSaSHI: 55 cm SaCRA telescope at Saitama University and MuSaSHI (r, i, z) Magnitudes of 99.9 above are the cases our pipeline failed to compute limiting magnitudes. OAOWFC also observed a couple of candidates reported in Andreoni et al, GCN Circ. 25362, and identified an object at the same position reported as DG19hqpgc. However, this source is visible in the PS1 archival image. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25390 SUBJECT: LIGO/Virgo S190814bv: Not observable by CALET DATE: 19/08/18 03:55:21 GMT FROM: Yuta Kawakubo at Louisiana State U./CALET S. Ozawa (Waseda U) A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration: At the trigger time of the compact binary merger candidate S190814bv, T0 = 2019-08-14 21:10:39.013 UT (The LIGO Scientific Collaboration and Virgo Collaboration, GCN Circ. 25324, 25333), the CALET Gamma-ray Burst Monitor (CGBM) high voltages were off (from T0-10 min to T0+7 min). The CALET Calorimeter (CAL) was operating in the high energy trigger mode at the trigger time of S190814bv, but the CAL FOV does not have any overlap with LVC probability significance map. The CAL FOV was centered at RA= 181.3 deg, DEC= 49.5 deg at T0. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25391 SUBJECT: LIGO/Virgo S190814bv: Prioritization of Counterpart Candidates based on a Photometric Redshift Analysis by the DECam-GROWTH Team DATE: 19/08/18 04:49:45 GMT FROM: Daniel Goldstein at Caltech D. A. Goldstein (Caltech), I. Andreoni (Caltech), R. Zhou (LBL), J. A. Newman (U. Pittsburgh), T. Ahumada (UMD), S. Anand (Caltech), M. Bulla (OKC), A. Dahiwale (Caltech), K. De (Caltech), S. Dhawan (OKC), A. K. H. Kong (NTHU), P. Gatkine (UMD), D. Perley (LJMU), Y. Sharma (Caltech), J. Sollerman (OKC), A. Tzanidakis (Caltech), K. Zhang (UCB), S. B. Cenko (NASA GSFC), C. Copperwheat (LJMU), M. W. Coughlin (Caltech), D. Kaplan (UWM), P. E. Nugent (LBL), M. M. Kasliwal (Caltech) report on behalf of the Global Relay of Observatories Watching Transients Happen (GROWTH) collaboration We estimated the photometric redshifts of the nearest static objects to over 151 detections of variability identified in subtractions produced by running the pipelines described in Goldstein, Andreoni et al. (2019) and Andreoni, Goldstein et al. (2019) on DECam images taken over the past three nights by the DESGW team (PI Soares-Santos, GCNs #25336, 25360). The observations covered the entire localization region to ~21 mag in i and z bands roughly six times over the past three nights. The redshifts have been determined by applying a random forest algorithm to the DECam Legacy Survey DR8 photometry (including both magnitude and size information) combined with spectroscopic redshifts from a variety of sources. Zhou et al. 2019 (in prep.) will provide a full description of the algorithm used. Restricting to the set of objects for which the nominal GW distance is within the 95% range of the photo-z’s luminosity distance (calculated assuming a Planck Collaboration [2015] cosmology), we find that only three DECam-GROWTH counterpart candidates remain: Candidates reported by Andreoni et al. (25362): DG19qabkc/AT2019nqc 01:29:03.67 -32:42:18.5 DG19wgmjc/AT2019npw 00:55:52.40 -25:46:59.8 Candidates newly reported in this GCN (reported earlier to TNS): DG19ayfjc/AT2019nqz 00:46:46.42 -24:20:12.1 We also estimated the photo-z of the remaining viable DESGW candidate, desgw-190814c, and find that its photo-z is consistent with the LIGO distance: desgw-190814c/AT2019nqq 01:23:49.22 -33:02:05.0 We encourage spectroscopy to classify these transients. -- Danny Goldstein http://astro.caltech.edu/~danny //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25392 SUBJECT: LIGO/VIRGO S190814bv: AbAO non-detection of AT2019nme DATE: 19/08/18 06:18:03 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI), A. Pozanenko (IKI), R. Ya. Inasaridze (AbAO), V.R. Ayvazian (AbAO), E. Mazaeva (IKI), A. Volnova (IKI), I. Molotov (KIAM) report on behalf of larger IKI GRB follow-up collaboration: We observed DESGW candidates desgw-190814a (AT2019nmd), desgw-190814b (AT2019nme) (Soares-Santos et al., GCN 25336) of the NSBH event S190814bv (The LIGO/Virgo Scientific Collaboration GCNs 25333, 25324) with AS-32 (0.7m) telescope of Abastumani Observatory starting on Aug. 16 (UT) 00:12:54. We obtained several 60 s exposures in R-filter per each candidate. In particular we do not detect the desgw-190814b (AT2019nme). Photometry of the field is following Name, TNS Name, MJD, Exposure (s), R_upper_limit (mag) desgw-190814b, 2019nme, 58711.03464, 12*60, 18.8 and based on nearby USNO-B1.0 stars (R2 magnitudes). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25393 SUBJECT: LIGO/Virgo S190814bv: Additional candidates identified in DECam images by the DECam-GROWTH team DATE: 19/08/18 19:19:30 GMT FROM: Daniel Goldstein at Caltech Danny Goldstein (Caltech), Igor Andreoni (Caltech), Matt Hankins (Caltech), Jesper Sollerman (OKC), Shreya Anand (Caltech), Tomas Ahumada (UMD), Jeffrey A. Newman (U. Pittsburgh), Dougal Dobie (U. Syd), Pradip Gatkine (UMD), Albert Kong (NTHU), David Kaplan (UWM), Ariel Goobar (OKC), Rongpu Zhou (LBL), Peter Nugent (LBL), Mansi Kasliwal (Caltech) on behalf of the GROWTH collaboration We continued the processing of the public data obtained by the DESGW team (GCN #25336, GCN #25360, GCN #25373) during the follow-up of the gravitational wave event S190814bv (GCN #25324) under the NOAO target of opportunity program 2019B-0372 (PI Soares-Santos). The data were processed using the image subtraction pipelines described in Goldstein, Andreoni et al. (2019) and Andreoni, Goldstein et al. (2019). We estimated the photometric redshifts of the nearest static objects by applying a random forest algorithm to Legacy Survey DR8 photometry (including both magnitude and size information) on DES imaging, combined with spectroscopic redshifts from a variety of sources. Zhou et al. 2019 (in prep.) will provide a full description of the algorithm used. In addition to the candidates already reported by our team (GCN #25362, GCN #25391), here we present a new set of candidates found within the 95% integrated probability area of the LIGO/Virgo LALInference skymap (GCN #25333) that were not previously reported on TNS or via GCN. The candidates are located far from known asteroids present in the Minor Planet Center and were detected at the same location on repeat visits separated by at least 30 minutes. +---------------------------------------------------------------------------------+ | name | IAU name | RA | Dec |filter| mag | MJD | notes | | +---------------------------------------------------------------------------------+ | DG19wxnjc | AT2019npv | 13.384651 | -23.832918 | z | 20.6 | 58713.34 | (a)(c)| | DG19gcwjc | AT2019ntp | 12.550301 | -26.197933 | i | 21.0 | 58713.25 | (a) | | DG19wlpmc | AT2019nsm | 10.875667 | -22.724820 | z | 21.3 | 58713.28 | (a) | | DG19sbzkc | AT2019ntr | 15.007850 | -26.714331 | z | 21.2 | 58713.27 | (a) | | DG19vodmc | AT2019nts | 12.131005 | -23.111334 | i | 20.3 | 58713.28 | (b) | | DG19rtekc | AT2019ntn | 23.722289 | -31.380485 | i | 20.8 | 58713.31 | (a) | | DG19hqhjc | AT2019nuj | 12.257240 | -23.234702 | i | 20.9 | 58713.28 | (c) | | DG19dnjlc | AT2019nuk | 13.740946 | -26.134614 | i | 21.6 | 58713.34 | (a)(c)| | DG19kpykc | AT2019nul | 13.818511 | -26.942936 | z | 20.2 | 58713.27 | (c) | | DG19rzhoc | AT2019num | 13.881677 | -22.969021 | i | 21.3 | 58713.36 | (a)(c)| | DG19tvtnc | AT2019nun | 14.202496 | -24.908467 | i | 22.3 | 58713.37 | (c) | | DG19kxdnc | AT2019nuq | 11.143987 | -22.029061 | z | 21.6 | 58713.29 | (c) | +---------------------------------------------------------------------------------+ (a) Offset from the possible host (b) Hostless (c) 95% confidence region from photo-z is consistent with 95% confidence region of LIGO distance. GROWTH is a worldwide collaboration comprising of Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, UK; TTU, USA; USyd, Australia; and SDSU, USA. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. We gratefully acknowledge Amazon, Inc. for a generous grant that funded our use of the Amazon Web Services cloud computing infrastructure to process the DECam data. -- Danny Goldstein http://astro.caltech.edu/~danny //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25394 SUBJECT: LIGO/Virgo S190814bv: DG19dnjlc is not offset from its host galaxy DATE: 19/08/18 19:30:56 GMT FROM: Daniel Goldstein at Caltech Danny Goldstein (Caltech) and Shreya Anand (Caltech) report on behalf of the GROWTH collaboration: We would like to issue the following correction to GCN 25393: DG19dnjlc should only be marked with note (c) [consistent photo-z], not notes (a) [offset from host] and (c). The corrected object table for GCN 25393 is as follows: +---------------------------------------------------------------------------------+ | name | IAU name | RA | Dec |filter| mag | MJD | notes | | +---------------------------------------------------------------------------------+ | DG19wxnjc | AT2019npv | 13.384651 | -23.832918 | z | 20.6 | 58713.34 | (a)(c)| | DG19rzhoc | AT2019num | 13.881677 | -22.969021 | i | 21.3 | 58713.36 | (a)(c)| | DG19gcwjc | AT2019ntp | 12.550301 | -26.197933 | i | 21.0 | 58713.25 | (a) | | DG19wlpmc | AT2019nsm | 10.875667 | -22.724820 | z | 21.3 | 58713.28 | (a) | | DG19sbzkc | AT2019ntr | 15.007850 | -26.714331 | z | 21.2 | 58713.27 | (a) | | DG19vodmc | AT2019nts | 12.131005 | -23.111334 | i | 20.3 | 58713.28 | (b) | | DG19rtekc | AT2019ntn | 23.722289 | -31.380485 | i | 20.8 | 58713.31 | (a) | | DG19hqhjc | AT2019nuj | 12.257240 | -23.234702 | i | 20.9 | 58713.28 | (c) | | DG19dnjlc | AT2019nuk | 13.740946 | -26.134614 | i | 21.6 | 58713.34 | (c) | | DG19kpykc | AT2019nul | 13.818511 | -26.942936 | z | 20.2 | 58713.27 | (c) | | DG19tvtnc | AT2019nun | 14.202496 | -24.908467 | i | 22.3 | 58713.37 | (c) | | DG19kxdnc | AT2019nuq | 11.143987 | -22.029061 | z | 21.6 | 58713.29 | (c) | +---------------------------------------------------------------------------------+ (a) Offset from the possible host (b) Hostless (c) 95% confidence region from photo-z is consistent with 95% confidence region of LIGO distance. We apologize for any confusion this may have caused. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25395 SUBJECT: LIGO/Virgo S190814bv: Keck/MOSFIRE NIR spectroscopy of DG19njmjc (= AT 2019nra) DATE: 19/08/18 20:17:48 GMT FROM: Georgios Dimitriadis at UCSC G. Dimitriadis, J. S. Brown, M. R. Seibert, R. J. Foley, D. A. Coulter, C. D. Kilpatrick, K. Siellez, C. Rojas-Bravo (UCSC) Report on behalf of the 1M2H and the UC-NASA-Keck collaborations: We obtained near-IR spectroscopy of DG19njmjc (= AT 2019nra), a transient spatially coincident with the localization of S190814bv (GCN #25324, GCN #25333), being approximately on the 55th percentile confidence contour, with the Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE) on the Keck I telescope on Maunakea, starting at UT 2019-08-18 14:24:52, aproximately 3.7 days after the LIGO/Virgo alert. Our spectrum covers the J-band (1.15-1.35 microns). The spectrum has relatively low S/N (S/N ~ 10), and appears featureless, with no obvious emission or absorption features. We thank the staff of Keck observatory, especially Carlos Alvarez, Randy Campbell, Jim Lyke, Alan Hatakeyama and John O'Meara, for facilitating this Target of Opportunity observation. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25396 SUBJECT: LIGO/Virgo S190814bv: WIRC NIR imaging follow-up of DECam transients DATE: 19/08/18 22:21:58 GMT FROM: Kishalay De at Caltech, GROWTH K. De (Caltech), S. Tinyanont (Caltech), N. Kamraj (Caltech), S. Pike (Caltech), C. Hopkins (Pasadena High School), M. M. Kasliwal (Caltech) report on behalf of the GROWTH collaboration We observed the locations of four transients reported from DECam searches of the localization region (GCN #25336, #25360, #25362, #25373, #25393) of LIGO / Virgo S190814bv (GCN #25324) with the Wide-field Infrared Camera (WIRC; Wilson et al. 2003) on the Palomar 200-inch Hale telescope. Observations were carried out between UT 2019-08-18 11:15 and 12:15, and consisted of a series of dithered exposures on the target fields in J band. The data were reduced and stacked using a custom reduction pipeline for WIRC (De et al. in prep) and we report preliminary magnitude estimates for the targets. Name Mag (AB) Notes DG19qabkc / AT 2019nqc 21.4 (1) DG19wgmjc / AT 2019npw 21.2 (2) desgw-190814c / AT 2019nqq 20.3 (2) DG19ayfjc / AT 2019nqz -- (3) Notes: (1) Transient is detected offset from host galaxy although host contamination cannot be ruled out (2) Transient visible on top of host galaxy, but magnitude estimates are contaminated with host galaxy light before template subtraction (3) Transient close to bright host nucleus, so no reliable transient photometry could be extracted before template subtraction //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25397 SUBJECT: LIGO/Virgo S190814bv: No candidates from image subtraction in DCT galaxy targeted search DATE: 19/08/19 02:01:19 GMT FROM: Simone Dichiara at UMCP/NASA/GSFC S.Dichiara (UMD, NASA-GSFC), E. Troja (UMD, NASA-GSFC), S.B. Cenko (NASA-GSFC), P. Gatkine (UMD), A. Kutyrev (UMD, NASA-GSFC), J.M. Durbak (UMD), S. Veilleux (UMD), Gabriele Minervini (INAF-IAPS), Roberto Ricci (IRA Bologna) report on behalf of a larger collaboration: We reobserved the fields listed in GCN 25374 using the Large Monolithic Imager (LMI) on the 4.3m Discovery Channel Telescope (DCT) at Happy Jack, AZ. Observations started on August 18, 10:09:02 UTC (about 3.54 days after the detection) with SDSS i filter. We do not find any obvious transient source down to i~21 AB mag for objects within the galaxy, and i~22 AB mag for field objects. We also observed the DECam-GROWTH candidates DG19qabkc and DG19wgmjc (Andreoni et al., GCN Circ. 25362; Goldstein et al., GCN Circ. 25391) in i and z band. Both objects are detected with i~21 AB mag, although photometric measurements are contaminated by host galaxy light. We thank the staff of the Discovery Channel Telescope in particular Ana Hayslip for assistance with these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25398 SUBJECT: LIGO/Virgo S190814bv: DESGW candidate update DATE: 19/08/19 06:35:16 GMT FROM: Ken Herner at Fermi Nat Accelerator Lab LIGO/Virgo S190814bv: DESGW candidate update Kenneth Herner, Antonella Palmese, Marcelle Soares-Santos, Douglas Tucker, Sahar Allam, James Annis, Alyssa Garcia, Robert Morgan, Tristan Bachmann, Dillon Brout, Luidhy Santana-Silva, Nora Sherman On behalf of the DESGW Team* As part of our ongoing CTIO Blanco/DECam search program, we observed the region of interest of the LIGO/Virgo black hole/neutron star merger S190814bv (initially reported by the LIGO/VIRGO Collaboration in GCN Circular No. 25324, and updated GCN Circular No. 25333) on the night of August 17 2019. Here we report an additional candidate counterpart (others were previously reported in GCN No. 25336, GCN No. 25373) and as well as detections of candidates previously reported by DECam-GROWTH (Andreoni et al. 25362, 25393). Images were processed by our difference imaging pipeline (Herner et al. 2017; see also Soares-Santos et al. 2015, 2017; Doctor et al. 2018; Morgan et al. 2019 for recent applications) using DES images as templates. We employ a machine learning code (autoscan, Goldstein et al. 2015) to reject subtraction artifacts. Candidates were initially selected by requiring at least two high signal to noise detections, rejecting asteroids. We then applied catalog-based vetting to reject variable stars, variable AGNs, using various catalogs including GAIA DR2, and candidates with hosts at redshifts inconsistent (>2sigma, H0=70) with the distance reported by the LVC for S190814bv (276 +/- 56 Mpc) using a variety of photometric and spectroscopic catalogs including DES. The final vetting was done via visual inspection. We matched our remaining candidates using the Transient Name Server to avoid reporting those previously reported by other groups, and the Minor Planet Center to further filter against slow moving asteroids. The following candidates pass our selection criteria: NAME TNS_NAME RA DEC MJD MAG desgw-190814f AT2019nte 23.557358 -31.7217 58711.297 20.95(i) The following candidates previously reported to the Transient Name Server also pass our selection criteria: NAME (GCN) TNS_NAME RA DEC desgw-190814c (25373) AT2019nqq 20.955072 -33.034722 DG19wgmjc (25362) AT2019npw 13.968327 -25.783283 DG19etlkc AT2019nqe 21.456741 -34.119553 DG19rzhoc (25393) AT2019num 13.881526 -22.969016 DG19rtekc (25393) AT2019ntn 23.722184 -31.380451 DG19wxnjc (25393) AT2019npv 13.384642 -23.832904 Further analysis is ongoing. *The DESGW Collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner, (Fermilab), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25400 SUBJECT: LIGO/Virgo S190814bv: No strong counterpart candidates in Swift/XRT observations DATE: 19/08/19 13:58:13 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester), J.A. Kennea (PSU), A. Tohuvavohu (PSU), S.D. Barthelmy (NASA/GSFC), A.P. Beardmore (U. Leicester), M.G. Bernardini (INAF-OAB), A.A. Breeveld (UCL-MSSL), P. Brown (TAMU), D.N. Burrows (PSU), S. Campana (INAF-OAB), S.B. Cenko (NASA/GSFC), G. Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB), V. D'Elia(ASDC), S.W.K. Emery (UCL-MSSL), P. Giommi (ASI), C. Gronwall (PSU), D. Hartmann (U. Clemson), H.A. Krimm (CRESST/GSFC/USRA), N.P.M. Kuin (UCL-MSSL), A.Y. Lien (GSFC/UMBC), F.E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), J.A. Nousek (PSU), S.R. Oates (U. Warwick), P.T. O'Brien (U. Leicester), J.P. Osborne (U. Leicester), C. Pagani (U. Leicester), K.L. Page (U.Leicester), M.J.Page (UCL-MSSL), D.M. Palmer (LANL), M. Perri (ASDC), J.L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU), M.H. Siegel (PSU), G. Tagliaferri (INAF-OAB), E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team: Swift has carried out 451 observations of the LVC error region for the GW trigger S190814bv convolved with the 2MPZ catalogue (Bilicki et al. 2014, ApJS, 210, 9), using 128 fields from the 'bayestar' GW localisation map and 323 fields from the 'LALInference.v1' GW localisation map. As these are 3D skymaps, galaxy distances were taken into account in selecting which ones to observe. The observations currently span from 11 ks to 385 ks after the LVC trigger, and the XRT has covered 20.1 deg^2 on the sky (corrected for overlaps). This covers 81% of the probability in the 'LALInference.v1' skymap, and 89% after convolving with the 2MPZ galaxy catalogue, as described by Evans et al. (2016, MNRAS, 462, 1591). Using the earlier 'bayestar' skymap our observations cover 70% of the probability (78% when convolved). Approximately 40% of the fields, covering 60% of the (galaxy convolved) GW probability, have been observed more than once. We have detected 40 X-ray sources. Each source is assigned a rank of 1-4 which describes how likely it is to be related to the GW trigger, with 1 being the most likely and 4 being the least likely. The ranks are described at https://www.swift.ac.uk/ranks.php. We have found: * 0 sources of rank 1 * 0 sources of rank 2 * 17 sources of rank 3 * 23 sources of rank 4 The Swift-XRT observations also covered the locations of 17 sources reported by other observers, thus: * DG19dnjlc (GCN25393) F < 1.7x10^-12 erg cm^-2 s^-1. * DG19gcwjc (GCN25393) F < 2.2x10^-12 erg cm^-2 s^-1. * DG19hqpgc (GCN25362) F < 4.2x10^-13 erg cm^-2 s^-1. * DG19kxdnc (GCN25393) F < 1.1x10^-12 erg cm^-2 s^-1. * DG19qabkc (GCN25362) F < 2.9x10^-12 erg cm^-2 s^-1. * DG19rtekc (GCN25393) F < 1.6x10^-12 erg cm^-2 s^-1. * DG19rzhoc (GCN25393) F < 4.1x10^-12 erg cm^-2 s^-1. * DG19sevhc (GCN25362) F < 4.4x10^-12 erg cm^-2 s^-1. * DG19tvtnc (GCN25393) F < 4.0x10^-12 erg cm^-2 s^-1. * DG19tzyhc (GCN25362) F < 1.2x10^-12 erg cm^-2 s^-1. * DG19wgmjc (GCN25362) F < 4.3x10^-12 erg cm^-2 s^-1. * DG19wlpmc (GCN25393) F < 4.3x10^-12 erg cm^-2 s^-1. * DG19wxnjc (GCN25393) F < 3.8x10^-12 erg cm^-2 s^-1. * desgw-190814a (GCN25336) F < 5.2x10^-12 erg cm^-2 s^-1. * desgw-190814d (GCN25373) Matches source 26, rank 3, 7.0" away. * desgw-190814e (GCN25373) F < 2.8x10^-12 erg cm^-2 s^-1. * desgw-190814f (GCN25398) F < 1.0x10^-12 erg cm^-2 s^-1. Flux limits are 3-sigma upper limits on the 0.3-10 keV observed flux. For all flux conversions and comparisons with catalogues and upper limits from other missions, we assumed a power-law spectrum with NH=3x10^20 cm^-2, and photon index (Gamma)=1.7 The results of the XRT automated analysis are online at https://www.swift.ac.uk/LVC/S190814bv Swift is currently re-observing the GW error region with longer exposures to look for any late-rising emission. This circular is an official product of the Swift XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25401 SUBJECT: LIGO/Virgo S190814bv: GRAWITA TNG NIR imaging of AT2019nqq and AT2019nqc DATE: 19/08/19 18:03:03 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, (INAF-OAB), A. Giunta (ASI/SSDC, INAF-OAR), L. Izzo (DARK/NBI), S. Piranomonte (INAF-OAR), E. Palazzi (INAF-OAS), L. Di Fabrizio, G. Mainella (INAF-TNG), Luca Malavolta (INAF-OACT) report on behalf of GRAWITA: We observed the targets listed below, within the updated 90% probability region of S190814bv (LIGO Scientific Collaboration and Virgo Collaboration, GCN Circ. 25333), with the 3.6m Italian TNG telescope (Canary Islands, Spain), equipped with the NICS infrared camera in imaging mode. ID RA, Dec: -------------------------------------------------- desgw-190814c / AT2019nqq 01:23:49.22 -33:02:05.0 DG19qabkc / AT2019nqc 01:29:03.67 -32:42:18.5 Observations were carried out on 2019 Aug 19 between 03:32 and 04:31 UT. These targets were reported as possible candidate counterparts of S190814bv (Andreoni et al., GCN Circ. 25362; Herner et al., GCN Circ. 25373; Dichiara et al., GCN Circ 25374; Tucker et al., GCN Circ. 25379; Goldstein et al., GCN Circ. 25391). We observed the two targets with the J filter, with an exposure of 20 minutes per target. With aperture photometry we measure for the source desgw-190814c / AT2019nqq a magnitude J= 20.0 +/- 0.2 (AB). We note that such a value can suffer from contamination from the host galaxy light. The source DG19qabkc / AT2019nqc is not detected down to a 3sigma limiting magnitude of J ~ 20.6 (AB). The photometry is calibrated against the 2MASS catalogue. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25409 SUBJECT: LIGO/Virgo S190814bv: No neutrino candidates at Pierre Auger Observatory DATE: 19/08/20 13:40:31 GMT FROM: Jaime Alvarez-Muniz at Pierre Auger Observatory J. Alvarez-Muniz, F. Pedreira, E. Zas (Univ. Santiago de Compostela, Spain), K. H. Kampert & M. Schimp (Bergische Universitat, Wuppertal, Germany) on behalf of the Pierre Auger Collaboration. In response to: LIGO/Virgo GW trigger S190814bv T0=2019-08-14 21:10:39 UTC We searched for Ultra-High-Energy (UHE) neutrinos with energies above ~ 1e17 eV in data collected with the Surface Detector (SD) of the Pierre Auger Observatory in a [-500,500] second interval about the LIGO-Virgo trigger S190814bv as well as 1 day after it. NO events survived the cuts applied to reject the background due to UHE Cosmic Rays i.e. NO NEUTRINO CANDIDATES WERE DETECTED. The field of view (fov) where the SD of Auger is sensitive to UHE neutrinos (corresponding to inclined directions with respect to the vertical relative to the ground) was NOT COINCIDENT with the LIGO/Virgo 90% localization region at the time T0 of the merger alert, achieving 100% OVERLAP at approximately T0+3.2 hours for a time period of approximately 2.7 hours. ------- The Pierre Auger Observatory is an UHE Cosmic Ray detector located in the Mendoza Province in Argentina. It consists of an array of Water Cherenkov detectors spread over a total surface of 3000 km^2 arranged in a triangular grid of 1.5 km side as well as Fluorescence telescopes and other systems (see 10.1016/j.nima.2015.06.058 for more information). For neutrino searches from GW events with Auger, please refer to: https://journals.aps.org/prd/pdf/10.1103/PhysRevD.94.122007 https://arxiv.org/abs/1906.07422 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25416 SUBJECT: LIGO/Virgo S190814bv: RATIR Optical observations of DECam transients DATE: 19/08/20 21:20:46 GMT FROM: Simone Dichiara at UMCP/NASA/GSFC Simone Dichiara (GSFC/UMD), Eleonora Troja (GSFC/UMD), Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), Diego Gonzalez (UNAM), Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM), Margarita Pereyra (UNAM), Gabriele Minervini (INAF-IAPS) and Tanner Wolfram (ASU) report: We observed the field of the optical transients detected with DECam (Goldstein et al., GCN Circ. 25393; Herner et al. 25373) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronomico Nacional on Sierra San Pedro Martir from 2019/08 20.30 to 2019/08 20.50 UTC, obtaining a total of about 10 minutes exposure on each field in the r band. We detect the following candidates with magnitudes: NAME START TIME EXP(sec) r_MAG ERR DG19sbzkc 07:16:14 1280 20.87 0.21 DG19gcwjc 08:18:23 1280 19.53 0.06 (a) desgw-190814e 08:57:59 1200 18.14 0.03 (a) desgw-190814c 09:28:55 1120 20.13 0.08 DG19rzhoc 10:03:38 1280 19.11 0.04 (a) DG19kpykc 10:35:55 1200 18.28 0.03 (a) DG19hqhjc 11:17:00 1280 20.79 0.12 (a) the object is in the central part of the galaxy Photometric measurements are contaminated by host galaxy light. We also observed at the position of DG19wlpmc and DG19rtekc, but we do not detect any object down to a magnitude of ~22 and ~21, respectively. These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the source. We thank the staff of the Observatorio Astronomico Nacional in San Pedro Martir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25417 SUBJECT: LIGO/Virgo S190814bv: Further Pan-STARRS observations and transient sources DATE: 19/08/20 21:44:10 GMT FROM: Stephen Smartt at Queen's U/Belfast S. Srivastav (QUB), M. Huber (IfA), S. J. Smartt, K. W. Smith (QUB), K. Chambers (IfA), D. R. Young, O. McBrien, J. Gillanders, D. O'Neil, P. Clark, S. Sim (QUB), T. de Boer, J. Bulger, J. Fairlamb, C.-C. Lin, T. Lowe, E. Magnier A. Schultz, R. J. Wainscoat, M. Willman, (IfA, University of Hawaii) A. Rest (STScI), C. Stubbs (Harvard) We report further observations of the LALInference skymap of the NSBH event S190814bv (The LIGO Scientific Collaboration and the Virgo Collaboration, GCN 25324, 25333) with the Pan-STARRS1 telescope (Chambers et al. 2016 arXiv :161205560C, Huber et al. GCN25356). Images were taken in the PS1 z-band between 2019-08-18 11:03:19 UT and 2019-08-18 14:54:11 UT (58713.46 - 58713.62). A sequence of 53 x 240 sec dithered exposures was taken covering the central (approximately) 50% probability region. Given the moon position, and the time lapsed after s190814bv, and the low probability of a bright transient at this epoch, we made the choice to focus on the central part of the skymap, with extra depth and one filter. The 240s sec exposures were combined into a single epoch stack, covering the GPC1 camera chip gaps. The images were processed with the IPP (Magnier et al. 2016, arXiv:1612.05240) and difference images for the co-added stacks were produced using the Pan-STARRS1 Science Consortium 3Pi data to detect transient objects. The median 5-sigma depth of the stacked sky cells was z < 21.6 (AB mag). We may be able to significantly improve on depth by collecting a deep reference frame during the next lunation. Standard filtering procedures, combined with a machine learning algorithm (Wright et al. 2015, MNRAS, 449, 451) were applied and all candidates were spatially cross-matched with known minor planets, and major star, galaxy, AGN and multi-wavelength catalogues (as described in Smartt et al. 2016, MNRAS, 462 4094). Given the extra depth compared to our first epoch (z < 20.4) on 2019-08-15 12:40:37 UT (58710.5282 ; see Huber et al. GCN 25356), we detected a significant number of fainter new transients, given in the table below. Examining potential host galaxies, and the weak constraints we have from earlier epoch data, we do not find a source that appears consistent with being a candidate for the counterpart to s190814bv. All candidates have been registered on the IAU TNS. We recovered several of the DECam GROWTH and DESGW transients (e.g. those reported in Goldstein et al. GCN 25393, Herner et al. GCN 25398 and related GCNs). We find that the combination of photometric evolution and redshift constraints (through possible hosts) leaves no obvious counterpart candidate for the objects in common. Name | TNS Name | RA (J2000) | Dec (J2000) | Disc MJD | z Mag err PS19epz | AT2019nuw | 00:50:26.34 | -25:52:57.8 | 58713.54 | 21.85 0.24 PS19eqa | AT2019nux | 00:50:21.01 | -23:42:46.7 | 58713.54 | 21.75 0.20 PS19eqc | AT2019nuz | 00:49:52.26 | -25:31:25.6 | 58713.54 | 21.89 0.22 PS19eqd | AT2019nva | 00:52:43.39 | -23:37:54.0 | 58713.54 | 21.49 0.18 PS19eqe | AT2019nvb | 00:46:51.16 | -25:25:39.3 | 58713.54 | 21.72 0.22 PS19eqf | AT2019nvc | 00:52:18.32 | -26:19:42.0 | 58713.54 | 21.31 0.18 PS19eqg | AT2019nvd | 00:55:42.30 | -24:41:50.2 | 58713.54 | 21.47 0.17 PS19eqh | AT2019nve | 00:56:05.51 | -24:38:26.3 | 58713.54 | 21.30 0.15 PS19eqo | AT2019nvr | 00:48:16.08 | -25:28:14.9 | 58713.54 | 20.89 0.13 PS19eqp | AT2019nvs | 00:52:37.75 | -26:11:41.4 | 58713.55 | 21.44 0.24 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25419 SUBJECT: LIGO/Virgo S190814bv: AT2019nqq 10.4m GTC spectroscopy DATE: 19/08/20 22:18:45 GMT FROM: Alberto J. Castro-Tirado at IAA-CSIC O. Lopez-Cruz (INAOE), A. J. Castro-Tirado (IAA-CSIC), L. Macri (TAMU), A. F. Valeev (SAO-RAS), E. Rios-Lopez (INAOE), Y.-D. Hu (IAA-CSIC), M. Diaz (UTRGV), E. Fernandez-Garcia (IAA-CSIC), V. Chabushyan (INAOE), A. Castellon (UMA), A. Watson (UNAM) and J. Font Serra (GRANTECAN, IAC, ULL), on behalf of three larger collaborations (including TOROS), report: Following the detection of AT2019nqq (Herner et al., GCNC 25373, 25398) within the error area of the GW event S190814bv (LVC, GCNC 25324), we obtained imaging and optical spectra covering the range 3700-10000 A with the 10.4m GTC telescope equipped with OSIRIS in La Palma (Spain) starting on Aug 20, 03:30 UT. The AT2019nqq spectrum (broad lines) is consistent with a SN IIP at 4 days post maximum at the nearby host galaxy redshift (z = 0.071 +/- 0.001, based on the narrow emission lines from the galaxy). Therefore we consider that AT2019nqq is unrelated to the GW event S190814bv. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25423 SUBJECT: LIGO/Virgo S190814bv: SOAR spectroscopy of AT2019noq and AT2019ntn DATE: 19/08/21 08:46:28 GMT FROM: Felipe Olivares Estay at MPE Ósmar Rodríguez (UNAB), Nicolás Meza-Retamal (ESO Chile), Jonathan Quirola (PUC), Felipe Olivares (INCT/UDA), Regis Cartier (NOAO/CTIO), Douglas Tucker (Fermilab), Marcelle Soares-Santos (Brandeis U), Clara Martinez-Vazquez (NOAO/CTIO), Alyssa Garcia (Brandeis U), Ken Herner (Fermilab), James Annis (Fermilab), Antonella Palmese (Fermilab), Nora Sherman (Fermilab and Brandeis U), Robert Morgan (U of Wisconsin-Madison), Tristan Bachmann (U Chicago), Tamara Davis (U Queensland) On behalf of the DESGW team*: We report SOAR Goodman spectroscopy of AT2019noq and AT2019ntn, possible counterparts to the black hole-neutron star merger S190814bv reported by the LVC in GCN Circulars No. 25324 and 25333. The candidates were found by the Pan-STARRS1 telescope (GCN Circular No. 25356), by the DECam-Growth team on CTIO Blanco DECam data (GCN Circular No. 25393), and independently in the DESGW analysis of the DECam data, respectively. We obtained 1800 and 900 sec exposures of AT2019noq and AT2019ntn, respectively, using the Goodman instrument on the 4.1m SOAR telescope at Cerro Pachón. The SNID classifier analysis of these spectra allows us to conclude that: AT2019noq (PS19epf) is consistent with a Type IIP SN at a redshift of 0.07 a few days after peak. AT2019ntn (DG19rtekc) is consistent with both a Type Ia-CSM SN and a Type IIn SN at z=0.1. The SOAR followup program is a partnership between the US (PIs: Tucker & Kilpatrick), Chilean (PI: Olivares), and Brazilian (PI: Makler) community. The optical counterpart was identified by the DECam Search & Discovery Program for Optical Signatures of Gravitational Wave Events (DESGW, PI: Soares-Santos), which is carried out by the Dark Energy Survey (DES) collaboration in partnership with wide ranging groups in the community. DESGW uses data obtained with the Dark Energy Camera (DECam), which was constructed by the DES collaboration with support from the Department of Energy and member institutions, and utilizes data as distributed by the Science Data Archive at NOAO. NOAO is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes do Brasil (MCTIC/LNA), the U.S. National Science Foundation's National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). *The DESGW Collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner, (Fermilab), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25425 SUBJECT: LIGO/Virgo S190814bv: further candidates from DESGW DATE: 19/08/21 11:50:30 GMT FROM: M. Soares-Santos at Fermi Lab Marcelle Soares-Santos, James Annis, Alyssa Garcia, Ken Herner, Antonella Palmese, Douglas Tucker, Sahar Allam, Robert Morgan, Tristan Bachmann, Nora Sherman, Clara Martinez, Tamara Davis *On behalf of the DESGW Team As part of our ongoing CTIO Blanco/DECam search program, on the night of August 20 2019 we observed the region of interest of the black hole/neutron star merger S190814bv reported by the LIGO/VIRGO Collaboration in GCN Circular No. 25324, and updated GCN Circular No. 25333. Here we report additional candidate counterparts to those we already reported in GCN Nos. 25336, 25373, & 25398. Images were processed by our difference imaging pipeline (Herner et al. 2017; see also Soares-Santos et al. 2015, 2017; Doctor et al. 2018; Morgan et al. 2019 for recent applications) using DES images as templates. We employ a machine learning code (autoscan, Goldstein et al. 2015) to reject subtraction artifacts. Candidates were initially selected by requiring at least two high signal to noise detections, rejecting asteroids. We then applied catalog-based vetting to reject variable stars, variable AGNs, using various catalogs including GAIA DR2, and candidates with hosts at redshifts inconsistent (>2sigma, H0=70) with the distance reported by the LVC for S190814bv (276 +/- 56 Mpc) using a variety of photometric and spectroscopic catalogs including DES. The final vetting was done via visual inspection. We matched our remaining candidates using the Transient Name Server to avoid reporting those previously reported by other groups, and the Minor Planet Center to further filter against slow moving asteroids. The following new candidates pass our selection criteria: Name | TNS Name | RA | Dec | MJD | Mag | MAGERR desgw-190814j | AT2019nxe | 11.570058 | -24.372554 | 58713.251 | 22.00 (z) | 0.02 desgw-190814m | AT2019nzr | 11.839208 | -24.576827 | 58713.247 | 23.78 (i) | 0.16 desgw-190814o | AT2019oab | 14.747491 | -25.770182 | 58716.220 | 23.54 (i) | 0.07 We encourage spectroscopic followup of these candidates as well as of desgw-190814f / AT2019nte (GCN 25398), our only previously reported counterpart candidate that remains viable after the follow-up described in the GCN archive. Further analysis is ongoing. *The DESGW Collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner, (Fermilab), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25437 SUBJECT: LIGO/Virgo S190814bv: No Optical Counterpart Candidates in Second-Epoch Lick/KAIT Observations DATE: 19/08/21 23:04:48 GMT FROM: Weikang Zheng at UC Berkeley Sergiy Vasylyev, Benjamin E. Stahl, Keto D. Zhang, Thomas de Jaeger, Yukei Murakami, Shaunak Modak, Kishore Patra, James Sunseri, Nachiket Girish, WeiKang Zheng, and Alexei V. Filippenko (UC Berkeley) report on behalf of the Lick/KAIT GW follow-up team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, performed second-epoch follow-up observations of the gravitational-wave event S190814bv (GCN 25324) detected by LIGO/Virgo on Aug. 18 UT, in addition to the first-epoch observations conducted on Aug. 15 (Vasylyev et al., GCN 25353). 52 galaxies were observed based on their priority scores and elevation visibility, with each clear-filter exposure time being 60 s. Our typical limiting magnitude is 18.0. No viable counterparts were identified and the analysis is ongoing. A full list of galaxies observed by KAIT is given below. GladeID UT(Aug18) RA_J2000 Dec_J2000 ----------------------------------------------- G0759372 09:43:15 00:44:14.1631 -25:06:33.2676 G0769196 10:16:17 00:49:23.1202 -26:30:26.9928 G0722022 10:36:40 00:53:44.8306 -27:36:18.306 G0648787 10:52:57 00:58:52.3109 -28:18:11.4696 G0744674 10:54:06 00:59:12.2695 -26:28:32.5092 G0678447 10:56:25 01:00:12.6631 -25:29:38.6376 G0621801 10:57:34 01:08:06.253 -27:37:43.3704 G0654768 10:59:53 01:15:28.2518 -30:22:28.0344 G0798266 11:01:02 01:17:59.3158 -30:45:45.4284 G0820330 11:02:11 01:18:15.4531 -30:46:28.4592 G0781747 11:03:23 01:20:07.6502 -32:55:51.8736 G0569298 11:04:32 01:20:15.8002 -30:11:07.9224 G0620221 11:19:09 01:22:11.3681 -31:32:34.5444 G0818640 11:20:18 01:22:29.1362 -32:43:02.0496 G0648167 11:21:28 01:22:31.0716 -31:19:02.0568 G0577695 11:22:37 01:23:01.4191 -31:08:15.5724 G0595298 11:23:46 01:23:14.8567 -32:50:28.6008 G1019706 11:24:58 01:23:40.9826 -31:20:33.5328 G0654122 11:26:07 01:24:33.2378 -31:21:58.6476 G0607401 11:27:16 01:24:34.5158 -33:10:24.6432 G0779486 11:28:28 01:24:50.3083 -31:45:23.8392 G0719778 11:29:37 01:24:55.1633 -30:37:15.8484 G0575310 11:30:46 01:25:37.1508 -30:21:55.7424 G0577764 11:31:55 01:25:47.5049 -30:02:04.0992 G0649850 11:33:05 01:26:45.6499 -32:53:47.742 G0682486 11:34:14 01:28:12.0859 -32:09:53.5356 G0689849 11:35:24 01:28:37.7206 -32:20:33.2844 G0971291 11:36:33 01:29:10.2703 -31:34:41.628 G0656725 11:37:40 01:29:22.2941 -32:50:57.6744 G1156151 11:38:50 01:30:08.341 -32:10:05.25 G0654024 11:39:59 01:30:11.9796 -32:54:13.2012 G0660500 11:41:08 01:31:45.2472 -32:24:56.2428 G0798774 11:42:18 01:32:04.3397 -33:48:10.3536 G0568433 11:43:27 01:32:21.4769 -31:05:32.3556 G0624721 11:45:47 01:32:58.309 -30:04:57.27 G0740474 11:46:57 01:34:01.9937 -33:26:37.5756 G0579643 11:48:08 01:34:04.2989 -32:48:31.554 G0805272 11:49:17 01:34:14.725 -31:38:56.112 G0568762 11:50:27 01:34:17.6906 -32:44:30.1164 G0664339 11:51:38 01:34:22.7609 -32:50:07.1376 G1428108 11:52:47 01:34:24.3581 -31:36:20.1348 G0235366 12:05:05 01:34:32.5068 -30:42:37.1232 G1435270 12:06:12 01:34:48.2006 -30:58:50.2356 G0651587 12:07:22 01:35:30.5822 -32:58:14.2032 G0658915 12:08:31 01:35:42.7565 -33:08:10.1976 G0638405 12:09:42 01:37:33.875 -32:13:45.5412 G0632982 12:10:51 01:37:49.3337 -32:54:36.5904 G0562220 12:12:01 01:38:28.5005 -33:36:28.9836 G0567443 12:13:13 01:39:30.4092 -34:02:25.9404 G0606993 12:14:22 01:39:52.207 -34:05:35.1924 G0554073 12:15:32 01:39:55.5854 -34:07:25.2084 G0033739 12:16:43 01:47:44.4682 -33:36:05.5152 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25438 SUBJECT: LIGO/Virgo S190814bv: new candidate from DESGW DATE: 19/08/21 23:59:24 GMT FROM: M. Soares-Santos at Fermi Lab Marcelle Soares-Santos, James Annis, Alyssa Garcia, Ken Herner, Antonella Palmese, Douglas Tucker, Sahar Allam, Robert Morgan, Tristan Bachmann, Nora Sherman, Clara Martinez, Tamara Davis, Melissa Butner *On behalf of the DESGW Team As part of our ongoing CTIO Blanco/DECam search program, on the night of August 20 2019 we observed the region of interest of the black hole/neutron star merger S190814bv reported by the LIGO/VIRGO Collaboration in GCN Circular No. 25324, and updated GCN Circular No. 25333. Here we report one additional candidate counterpart to those we already reported in GCN Nos. 25336, 25373, 25398, 25425. Images were processed by our difference imaging pipeline (Herner et al. 2017; see also Soares-Santos et al. 2015, 2017; Doctor et al. 2018; Morgan et al. 2019 for recent applications) using DES images as templates. We employ a machine learning code (autoscan, Goldstein et al. 2015) to reject subtraction artifacts. Candidates were initially selected by requiring at least two high signal to noise detections, rejecting asteroids. We then applied catalog-based vetting to reject variable stars, variable AGNs, using various catalogs including GAIA DR2, and candidates with hosts at redshifts inconsistent (>2sigma, H0=70) with the distance reported by the LVC for S190814bv (276 +/- 56 Mpc) using a variety of photometric and spectroscopic catalogs including DES. The final vetting was done via visual inspection. We matched our remaining candidates using the Transient Name Server to avoid reporting those previously reported by other groups, and the Minor Planet Center to further filter against slow moving asteroids. The following new candidate pass our selection criteria: Name | TNS Name | RA | DEC | MJD | MAG | MAGERR desgw-190814q | AT2019obc | 14.566764 | -24.139771 | 58716.191 | 22.02 (i) | 0.01 This candidate is particularly interesting because its light curve has peaked between 3 and 5 days post merger. We encourage spectroscopic followup of this candidate as well as of candidates desgw-190814j, desgw-190814m, desgw-190814o, desgw-190814f which we reported in (GCN Nos. 25425, 25398). Further analysis is ongoing. *The DESGW Collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner, (Fermilab), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25443 SUBJECT: LIGO/Virgo S190814bv: a potential faint optical counterpart in CFHT imaging DATE: 19/08/22 04:43:16 GMT FROM: Maria R Drout at Carnegie Observatories J. Ruan (McGill U.), N. Vieira (McGill U.), D. Haggard (McGill U.), M. R. Drout (U. of Toronto), N. Asfari (U. of Toronto), R. Carlberg (U. of Toronto), R. Doyon (U. de Montreal), R. Fernandez (U. of Alberta), B. Gaensler (U. of Toronto), V. Kaspi (McGill U.), D. Lafreniere (U. de Montreal), C. Matzner (U. of Toronto), D-S. Moon (U. of Toronto), C. Ni (U. of Toronto), M. Nynka (MIT), A. L. Piro (Carnegie Obs.), S. Safi-Harb (U. of Manitoba), K. Spekkens (RMC/Queen’s U.) We report on optical imaging obtained on the MegaPrime/MegaCam instrument (1x1 deg FOV) at the Canada-France-Hawaii Telescope, to search for a counterpart to the candidate gravitational wave source S190814bv. We obtained deep images for the entire updated 50% confidence localization region (GCN 25333) in g-band on UTC 2019-08-16 (1.7 days post-merger), in i-band on UTC 2019-08-18 (3.6 days post-merger), in i-band on UTC 2019-08-19 (4.6 days post-merger), and in both i- and z-band on 2019-08-21 (6.6 days post-merger). In each of those nights, we also obtained images of a few additional galaxies in the larger 90% confidence localization region. We stacked the images from each night and calibrated based on the Pan-STARRS 3pi Survey. For an initial search, we visually inspected the galaxies in our stacked images from the GLADE catalog (Dayla et al., 2018), based on a candidate host-galaxy prioritization scheme. We find one potential faint counterpart lying near the possible host-galaxy 2MASX J00472894-2526263, which is located at (RA, Dec = 11.870618, -25.440655) and a distance of 267 Mpc. This galaxy was the 5th highest-ranked candidate host-galaxy in the LIGO/Virgo localization region from the GLADE catalog based on our prioritization scheme. The potential counterpart is at ~17” away from the center of this galaxy, and is located at (RA, Dec = 11.866781, -25.437264). The potential counterpart was not detected in our g-band imaging at 1.7 days post-merger, but was subsequently detected in i-band at 3.6, 4.6, and 6.6 days post-merger, and in z-band at 6.6 days post-merger. A table of our aperture photometry measurements is provided below: UTC, days post-merger, band, mag 2019-08-16, 1.7, g, >22.8 2019-08-18, 3.6, i, 22.86+/-0.19 2019-08-19, 4.6, i, 22.80+/-0.23 2019-08-21, 6.6, i, 22.93+/-0.12 2019-08-21, 6.6, z, 22.24+/-0.30 Cutouts of our images can be found at this link: http://www.physics.mcgill.ca/~jruan/S190814bv/cutouts_rank4.png We also visually examined deeper reference images from DECam taken as part of the DECaLS/DESI Legacy Imaging Surveys, in g-, r- and z-bands. Our candidate counterpart from CFHT is also not detected in these DECam reference images. We note that these deep DECam reference images reveal another source (which we label T1 in our cutouts below) that is ~4.5” away from our possible counterpart. This T1 source is also clearly detected in our i-band images at 6.6 days post-merger, and is not the same object as our potential counterpart. Cutouts showing the clear positional offsets between T1 and the potential counterpart can be found at this link: http://www.physics.mcgill.ca/~jruan/S190814bv/cutouts_rank4_DECam.png Further follow-up of this potential counterpart is encouraged. We are continuing observations, and analysis will be reported. We thank the CFHT queued service observing team and the telescope staff for their help in obtaining these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25445 SUBJECT: LIGO/Virgo S190814bv: No radio counterpart detected in ASKAP observations DATE: 19/08/22 07:57:20 GMT FROM: Dougal Dobie at VAST Dougal Dobie (University of Sydney/CSIRO), Adam Stewart (University of Sydney), Ziteng Wang (University of Sydney), Tara Murphy (University of Sydney),Emil Lenc (CSIRO), David Kaplan (UWM), Aidan Hotan (CSIRO), Kunal Mooley (NRAO, Caltech), Gregg Hallinan (Caltech), David McConnell (CSIRO), Julie Banfield (CSIRO), Wasim Raja (CSIRO), Matthew Whiting (CSIRO), Vanessa Moss (CSIRO), Igor Andreoni (Caltech) and the OzGrav, JAGWAR and GROWTH collaborations. We report observations of the localisation region of S190814bv (LVC, GCN 25324) with the Australian Square Kilometre Array Pathfinder (ASKAP) on 2019-08-16 at a central frequency of 943 MHz with a bandwidth of 288 MHz. We have observed a single 30 sq. deg. field centered on RA = 00:50:37.5 Dec = -25:16:57.4 which covers approximately 85% of the sky localisation from the LALInference skymap (GCN 25333), with a median rms of 34 uJy. We have searched for radio emission within 5 arcseconds of the location of the 124 optical transients reported on the Transient Name Server by the DECam-GROWTH and DESGW teams between 2019-08-16 and 2019-08-22 as at 2019-08-22 03:00 UTC. We report coincident compact radio emission at the location of 14 of them: | Name | RA | Dec | Int. Flux (uJy) | err. (uJy) | Notes | | AT 2019nqa | 00:52:39.1 | -25:00:15 | 258 | 30 | | | AT 2019nqy | 00:56:23.2 | -24:41:11 | 393 | 29 | | | AT 2019nqz | 00:46:46.5 | -24:20:12 | 870 | 30 | (a) | | AT 2019nsr | 00:57:27.6 | -26:16:44 | 290 | 36 | (c) | | AT 2019nto | 00:42:03.5 | -24:48:19 | 342 | 28 | (c) | | AT 2019nuk | 00:54:57.9 | -26:08:03 | 233 | 28 | (b) | | AT 2019nul | 00:55:16.4 | -26:56:35 | 204 | 28 | (b) | | AT 2019nun | 00:56:48.7 | -24:54:31 | 377 | 29 | (b,c) | | AT 2019nuo | 00:56:03.9 | -23:18:15 | 388 | 36 | (c) | | AT 2019nup | 00:55:04.3 | -26:46:12 | 446 | 33 | (c) | | AT 2019nzj | 00:52:05.3 | -26:11:03 | 759 | 29 | | | AT 2019nzn | 00:55:19.9 | -24:09:29 | 233 | 32 | (c) | | AT 2019oay | 00:45:25.2 | -25:53:43 | 348 | 31 | | | AT 2019ocs | 01:00:11.4 | -25:53:22 | 352 | 29 | | (a) reported in GCN25391 (b) reported in GCN25393 (c) source possibly extended We have also performed a preliminary search for transients using TraP (Swinbank et al. 2015) comparing this observation to the Rapid ASKAP Continuum Survey (RACS, [1]) at a detection threshold of 0.95 mJy, corresponding to 5 times the lowest rms of the RACS image. We find one candidate transient located at RA = 00:54:34.6 +/- 0.02 arcsec Dec = -28:02:35.3 +/- 0.01 arcsec which we note is outside the 95% confidence region of S190814bv. We measure a flux density of 3.4 mJy in this observation and a local rms noise of 0.25 mJy in the 888 MHz RACS image observed on 2019-04-26. We measured an integrated flux density of 0.74 mJy in the RACS image using TraP. We also note that there is a radio source coincident with this location in the image from the Very Large Array Sky Survey (VLASS) observed on 2019-06-29 with a flux density of ~1.6 mJy at 3 GHz. We conducted follow-up of this source with the Australia Telescope Compact Array (ATCA) on 2019-08-21 with two 2048 MHz bands centered on 5.5 and 9 GHz. We measure preliminary flux densities of 2.88 +/- 0.03 mJy and 2.93 +/- 0.02 mJy at 5.5 and 9 GHz, with respective in-band spectral indices of +0.17 and -0.37. Combining the near-contemporaneous ATCA and ASKAP measurements we find a flat spectral index. Based on these observations this candidate is likely to be an unrelated AGN. The ASKAP observation is publicly available on the CSIRO ASKAP Science Data Archive [2] under Scheduling Block ID 9602. Further analysis of this ASKAP observation is ongoing and further epochs are planned. Thank you to CSIRO staff for supporting these observations. [1] https://www.atnf.csiro.au/content/racs [2] https://casda.csiro.au/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25447 SUBJECT: LIGO/Virgo S190814bv: ENGRAVE VLT/HAWK-I observations and archival detection of the CFHT candidate DATE: 19/08/22 14:06:23 GMT FROM: Daniele B Malesani at DTU Space J. Japelj (Univ. of Amsterdam), Z. Jin (PMO), E. Kankare (Univ. Turku), E. Kool (OKC), A. J. Levan (Radboud Univ.), K. Maguire (TCD), D. B. Malesani (DTU Space), S. Mattila (Univ. Turku), B. Milvang-Jensen (DAWN/NBI), T. Reynolds (Univ. Turku), N. B. Sabha (Univ. Innsbruck), A. Sagues Carracedo (Stockholm Univ.), report on behalf of the ENGRAVE collaboration: ENGRAVE targeted 9 fields containing 17 high-probability host galaxies for S190814bv, based on the LALInference skymap (LIGO Scientific Collaboration and Virgo Collaboration, GCN 25333), with deep VLT/HAWK-I imaging over two epochs in a search for intrinsically faint, near infrared transient sources. As part of this search, we observed the host galaxy 2MASX J00472894-2526263 of the Canada-France-Hawaii Telescope (CFHT) candidate reported by Ruan et al. (GCN 25443). The observations were conducted between 06:55 and 07:14 UT on 2019-08-16 and a second epoch between 04:32 and 04:50 UT on 2019-08-21, approximately 1.4 and 6.3 d after S190814bv, respectively (600 s exposure per epoch in the Ks filter). The source is detected in both epochs with AB magnitudes of 21.0 +- 0.1 and 20.9 +- 0.1, respectively (based on preliminary photometry calibrated against the 2MASS catalogue). This field was also covered serendipitously by the ESO/VISTA survey telescope in the Ks band during the science verification program. The CFHT candidate is detected in images from 2009-10-23 and 2009-10-30. We measure a brightness around 0.5 mag fainter in the historic data compared to the HAWK-I measurement. This confirms some level of long-term variability, consistent with the report by Ruan et al. (GCN 25443). The lack of variability between the two VLT/HAWK-I images and especially the archival detection suggest that this object is unrelated to S190814bv. We acknowledge the ESO observing staff at Paranal, in particular S. Brillant, J. Corral-Santana, B. Haussler, C. Opitom, F. J. Selman, and T. Szeifert. Based on observations collected by the ENGRAVE collaboration at the European Southern Observatory under ESO program 0103.D-0722 (for further information on ENGRAVE see http://www.engrave-eso.org/). The VISTA data were secured under science verification program 60.A-9285(A). We acknowledge valuable help with the archival VISTA data by Carlos Gonzalez-Fernandez (CASU / IoA Cambridge). [GCN OPS NOTE(23aug19): Per author's request, The "Drout" references in the 1st and 3 paragraphs were changed to "Ruan".] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25449 SUBJECT: LIGO/Virgo S190814bv: NIR imaging follow-up of ASKAP transient DATE: 19/08/22 17:44:26 GMT FROM: Kishalay De at Caltech, GROWTH K. De (Caltech), S. Tinyanont (Caltech), M. Nguyen (UC Berkeley), S. Palatnick (University of Pennsylvania), M. Millar-Blanchaer (JPL, Caltech), R. Doiron (Barks University), K. Mooley (Caltech), M. Kasliwal (Caltech) report on behalf of the GROWTH and JAGWAR collaborations We observed the field of the radio transient found in ASKAP follow-up (GCN #25445) of the localization region of LIGO/Virgo S190814bv (GCN #25324) with the Wide field Infrared Camera (WIRC; Wilson et al. 2003) on the Palomar 200-inch telescope. We obtained a series of dithered exposures of the field in J band for a total exposure time of 10 minutes. The data were reduced and stacked using a custom data reduction pipeline for WIRC (De et al. in prep). No source is detected at the reported location down to a 5 sigma limiting magnitude of 21.5 AB mag. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25454 SUBJECT: LIGO/Virgo S190814bv: WHT spectroscopy of the host of AT2019npv DATE: 19/08/23 11:00:53 GMT FROM: Kate Maguire at Trinity College Dublin P. Jonker (SRON/Radboud Univ), K. Maguire (TCD), M. Fraser (UCD), M.A.P. Torres (IAC/ULL/SRON), A. J. Levan (Radboud Univ), A. Shlentsova (Radboud Univ) report on behalf of the GW@WHT collaboration: We obtained spectroscopy of the host galaxy of AT2019npv (DG19wxnjc) discovered in DECam images within the LIGO/Virgo S190814bv sky localisation (GCN 25333). It was first reported by Goldstein et al. (GCN 25393) at magnitude 20.6 in the z band on MJD 58713.34 with a photo-z measurement placing it within the 95% confidence region of the LIGO/Virgo distance. The transient was confirmed in Herner et al. (GCN 25398). Two spectra of the host were obtained on 2019-08-22 using the ACAM instrument mounted on the William Herschel Telescope located at the Roque de Los Muchachos Observatory, La Palma, Spain. The spectra both show weak emission consistent with Halpha at a redshift of 0.056 (250 Mpc), confirming its location spectroscopically within the most up-to-date distance range based on the GW signal of S190814bv of 267 +- 52 Mpc. The emission feature appears extended in the 2D spectra. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25455 SUBJECT: LIGO/Virgo S190814bv: Further Pan-STARRS z-band observations and AT2019npv photometry DATE: 19/08/23 13:03:24 GMT FROM: Stephen Smartt at Queen's U/Belfast S. Smartt, K. W. Smith, S. Srivastav (QUB), T.-W. Chen (MPE), M. Huber (IfA), , K. Chambers (IfA), D. R. Young, O. McBrien, J. Gillanders, D. O'Neil, P. Clark, S. Sim (QUB), T. de Boer, J. Bulger, J. Fairlamb, C.-C. Lin, T. Lowe, E. Magnier A. Schultz, R. J. Wainscoat, M. Willman, (IfA, University of Hawaii) A. Rest (STScI), C. Stubbs (Harvard), We made further observations of the LALInference skymap of the NSBH event S190814bv (The LIGO Scientific Collaboration and the Virgo Collaboration, GCN 25324, 25333) with the Pan-STARRS1 telescope (Chambers et al. 2016, Huber et al. GCN25356) on MJD 58716.5. As described in Srivastav et al. (GCN 25417), we focused on the inner 50% probability with deep stacks reaching a typical 5-sigma limiting magnitude of z < 22.2. We found one more. previously unreported transient at z = 21.41 +/- 0.15, with details available on the TNS (AT2019ofb). Here we report the photometric evolution of the transient AT2019npv (DG19wxnjc), discovered by DECam-GROWTH (Goldstein et al. GCN25393). Jonker et al. (GCN 25454) measured the redshift of the nearby blue galaxy (PSO J013.3850-23.8322 or GALEXASC J005332.30-234955.3) to be z = 0.056, placing it within the distance range of S190814bv. The following table contains the z-band photometry reported to date and new PS1 measurements. 58710.58 ~20.8 PS1,marginal 2-3 sigma detection in z (mag uncertain) 58711.3 20.7 DECam (TNS Trans. Report 1507) 58713.34 20.6 DECam (GCN 25393) 58713.54 21.3 PS1 58716.54 21.5 PS1 The DECam photometry needs checked on 58713.34. The last two PS1 points have uncertainties of +/- 0.2 mag. The first has an error of 0.3 to 0.4 mag. Within the uncertainties, there could be a slow fade of around 0.1 mag per day, but fast fading can be ruled out with a clear detection on 58716.54. Spectra of this faint object is still difficult due to the moon position. However it should still be pursued, as this appears to be one of the only remaining viable counterpart candidates. We note the existence of another possible host galaxy. The transient would be about 40kpc from 2MASS J00533400-2350224, if both were at about ~250 Mpc. 2MASS J00533400-2350224 13.391293 -23.839395 V = 18.6 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25457 SUBJECT: LIGO/Virgo S190814bv: GROND follow-up observations of AT2019npv DATE: 19/08/23 15:20:12 GMT FROM: Ting-Wan Chen at MPE T.-W. Chen (MPE), T. Schweyer (MPE), A. Nicuesa Guelbenzu (TLS Tautenburg), P. Schady (Bath), A. Rau (MPE), J. Bolmer (MPE), S. Klose (TLS Tautenburg) report: We observed the counterpart candidate AT2019npv (=DG19wxnjc; GCN #25393, Goldstein et al.; GCN #25398, Herner et al.) of S190814bv (GCN #25324) simultaneously in g'r'i'z'JHKs with GROND (Greiner et al. 2008, PASP 120, 405) mounted on the 2.2 m MPG telescope at ESO La Silla Observatory (Chile). The redshift of the galaxy nearby to AT2019npv is consistent within the distance range of S190814bv (GCN #25454, Jonker et al.). Observations were obtained between 19 and 23 August 2019, 4.4, 5.4 and 8.3 days after the S190814bv detection. The magnitudes are measured using aperture photometry with a aperture size of 1*FWHM of the average of the field stars (seeing 0".99, 0".84, and 0".79, resp.). We caution that the magnitudes contain underlying host-galaxy light. Given magnitudes are calibrated against Pan-STARRS field stars in the optical and against 2MASS field stars in the NIR. All magnitudes are given in the AB system. The magnitudes are not corrected for Galactic foreground extinction corresponding to a reddening of E_(B-V) = 0.02 mag in the direction of the counterpart (Schlafly & Finkbeiner 2011). In terms of no detection, we measured the host-galaxy backgrond light at the transient position. MJD g' r' i' z' 58714.328 21.55 (0.08) 21.06 (0.11) 21.26 (0.10) 20.67 (0.12) J H Ks 20.82 (0.18) >21.0 >20.2 MJD g' r' i' z' 58715.246 21.82 (0.05) 21.18 (0.11) 21.10 (0.07) 20.82 (0.13) J H Ks 20.77 (0.14) 20.90 (0.27) >20.3 MJD g' r' i' z' 58718.203 21.83 (0.04) 21.03 (0.14) 21.20 (0.05) 20.89 (0.13) J H Ks 21.01 (0.17) >21.2 >20.2 Over the timescale of our observations we do not detect any significant variation in the brightness of this object. We note that our z'-band magnitude is slightly brighter compared to PanSTARRS (GCN #25455, Smartt et al.), because we did not perform any host template subtraction. We acknowledge excellent help in obtaining these data from Angela Hempel and Regis Lachaume on La Silla. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25458 SUBJECT: LIGO/Virgo S190814bv: DESGW photometry of AT2019npv DATE: 19/08/23 16:23:11 GMT FROM: James Annis at Fermilab James Annis, Ken Herner, Marcelle Soares-Santos, on behalf of the DESGW Team report: The counterpart candidate AT2091pv, reported by Goldstein et al (GCN 25393) is near a galaxy at a z=0.056 (Jonker et al, GCN 25454), which is consistent with the LIGO distance for S190814bv of 267 +- 52 Mpc (GCN 25324, GCN. 25333). Smartt et al (GCN 25455) report on Pan-STARRS z-band photometry in an effort to build a light curve, and further data is reported by Chen et al (25457). Here we provide additional, independent photometry for the object from the DECam images, which we obtained over 4 epochs. We obtained several images of the region during the course of each night. We coadded all images from a given night and bandpass to provide improved S/N. The MJD below refers to the first exposure from each night; subsequent exposures on a given night were separated by either ~30 or ~60 minutes. We did not detect the transient on the first night of observations (MJDs of 58710.27 to 58710.34), likely due to poor observing conditions. MJD | Band | Mag | MAGERR 58711.247 | i | 21.40 | 0.02 58712.220 | i | 21.54 | 0.02 58712.297 | z | 21.31 | 0.02 58713.262 | i | 21.61 | 0.02 58716.191 | i | 21.69 | 0.02 58716.193 | z | 21.25 | 0.01 These are observed magnitudes, not corrected for reddening. Our z-band photometry is consistent with the Pan-STARRS within errors. Our i and z band data is fainter than the Grond photometry by 2sigma using their errors, likely due to their magnitudes containing galaxy light. We note that the high quality i-band photometry is consistent with fading of 0.1 mag/day. Our i-band light curve is well described by the following polynomial: i-mag = -0.314 x**2 + 0.6951 x - 0.06361, where x = log10(mjd-58710) The decline seems to be flattening out, and our fit suggests i=21.7 tonight. *The DESGW Collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner, (Fermilab), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25460 SUBJECT: LIGO/Virgo S190814bv: Photometric Evolution of DECAM candidates DATE: 19/08/23 22:37:38 GMT FROM: Mansi M. Kasliwal at Caltech/Carnegie C. Fremling, D. Goldstein, I. Andreoni, M. M. Kasliwal (Caltech) report on behalf of the GROWTH (Global Relay of Observatories Watching Transients Happen) collaboration We ran independent, offline, forced photometry (Fremling et al. 2016) of some candidates (Goldstein et al., GCN 25393, Herner et al., GCN 25373, Soares-Santos et al., GCN 25438, Andreoni et al., GCN 25362) from the Dark Energy Camera that have a photometric redshift consistent with the GW constraint for S190814bv (GCN LVC et al., 25324, 25333). The following candidates are consistent with flat evolution within error bars of typically 0.15 mag: DG19wgmjc/AT2019npw , DG19wxnjc/AT2019npv, DG19rzhoc/AT2019num, desgw-190814q/AT2019obc. This photometry is consistent within the uncertainties with Annis et al., GCN 25458 and Smartt et al. GCN 25455. We caution that previous photometry reported by our discovery pipeline to TNS esp. on the first two nights was preliminary and affected by weather. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25461 SUBJECT: LIGO/Virgo S190814bv: Keck NIRES spectroscopy of DG19wxnjc/AT2019npv DATE: 19/08/24 13:57:14 GMT FROM: Mansi M. Kasliwal at Caltech/Carnegie K. De, M. M. Kasliwal, I. Andreoni, V. Karambelkar, Y. Sharma (Caltech) report on behalf of the GROWTH (Global Relay of Observatories Watching Transients Happen) collaboration We observed DG19wxnjc/AT2019npv (Goldstein et al. GCN 25393) with NIRES (Wilson et al. 2004) on the Keck II telescope starting 2019-08-24 11:41 UT. The host galaxy redshift (Jonker et al. GCN 25454) and light curve (Annis et al. GCN 25458, Smartt et al. GCN 25455, Chen et al. GCN 25457) hinted at a possible association with the neutron star black hole merger S190814bv (LVC et al. GCN 25324, GCN 25333). Our on-source integration time with Keck/NIRES was 40min. We see a mostly featureless continuum from the transient from 0.94 to 2.45 microns. There is possibly a Helium feature around 10830A, however, it could be an artifact due to proximity to a telluric feature. Given the lack of obvious identifiable features, we encourage deep optical spectroscopy to distinguish between a kilonova origin or supernova origin. We are grateful to the W. M. Keck Observatory staff, especially Greg Doppmann and Terry Stickel, for facilitating this partnership target of opportunity observation. We thank the observer Leslie Young for her kind co-operation. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25468 SUBJECT: LIGO/Virgo S190814bv: Archival detection of DG19wxnjc/AT2019npv in DES data DATE: 19/08/24 21:30:22 GMT FROM: Antonella Palmese at Fermilab Antonella Palmese, James Annis, Marcelle Soares-Santos on behalf of the DESGW Team We visually inspected DES Year 5 coadded image at the position of LIGO/Virgo S190814bv and identified DG19wxnjc/AT2019npv, even if the source is not clearly visible or very faint in some of the single epoch images. All the exposures used in the coadd were taken previously to the detection of S190814bv. The archival detection suggests that AT2019npv is not related to S190814bv. *The DESGW Collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner, (Fermilab), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25472 SUBJECT: LIGO/Virgo S190814bv: No radio counterpart to DG19wxnjc/AT2019npv in ASKAP observations DATE: 19/08/25 04:26:24 GMT FROM: Dougal Dobie at VAST Dougal Dobie (University of Sydney/CSIRO), Tara Murphy (University of Sydney), Emil Lenc (CSIRO), David Kaplan (UWM), Aidan Hotan (CSIRO), Adam Stewart (University of Sydney) and the OzGrav, JAGWAR and GROWTH collaborations. We report a non-detection of the optical transient DG19wxnjc/AT2019npv (GCN 25393) in two recent observations with the Australian Square Kilometre Array Pathfinder (ASKAP) at a frequency of 943 MHz. The 3-sigma upper limits at the position of this source are 75 uJy on 2019-08-16 and 96 uJy on 2019-08-23. Both observations were a 30 sq. deg. field of the localisation region of S190814bv (LVC, GCN 25324) centered on RA = 00:50:37.5 Dec = -25:16:57.4 with a central frequency of 943 MHz with a bandwidth of 288 MHz, as reported in GCN 25445. Further analysis of these ASKAP observations are ongoing and future epochs are planned. Thank you to CSIRO staff for supporting these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25474 SUBJECT: LIGO/Virgo S190814bv: MASTER prediscovery and postdiscovery observations DECam candidate DG19wxnjc/AT2019npv field DATE: 19/08/25 15:40:32 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, D. Vlasenko, E. Gorbovskoy, F.Balakin, N.Tyurina, V. Kornilov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V. Vladimirov, D.Zimnukhov, V. Senik, A.Chasovnikov, A.Pozdnyakov,D.Kuvshinov, V. Topolev (Lomonosov Moscow State University, SAI, Physics Department), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias IAC), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), H. Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), D. Buckley (South African Astronomical Observatory SAAO), N.M. Budnev, O. Gress, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University) All observations was done under the MASTER target of opportunity program that includes the results of population synthesis by Scenario Machine (Lipunov et al., "First LIGO events: binary black holes mergings", New Astronomy, Vol. 2, p. 43-52, 1997). There are number arhive images just before trigger. One (GCN 25354) of our previous circulars was sent erroneously. Here we give the correct schedule of our observations. MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the LIGO/Virgo S190814bv errorbox 1327 sec after trigger time at 2019-08-14 21:32:46 UT (Lipunov et al., GCN 25322). MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) started inspect of the LIGO/Virgo S190814bv errorbox 1351 sec after trigger time at 2019-08-14 21:33:10 UT, with upper limit up to 19.4 mag (Lipunov et al., GCN 25322). MASTER-Tavrida robotic telescope located at Crimea started inspect of the LIGO/Virgo S190814bv errorbox 1373 sec after trigger time at 22019-08-14 21:33:32 UT. MASTER-IAC robotic telescope located at Tenerife (Spain) started inspect of the LIGO/Virgo S190814bv errorbox 4200 sec after trigger time at 2019-08-14 22019-08-14 22:20:39 UT. Our coadded images limit is: 10367 | 2019-08-15 00:01:56 | C | 1440 | 20.6 | Coadd 11174 | 2019-08-15 00:12:22 | C | 540 | 19.9 | Coadd 22253 | 2019-08-15 03:20:01 | C | 360 | 19.3 | Coadd 87165 | 2019-08-15 21:23:44 | C | 360 | 18.5 | Coadd 97387 | 2019-08-16 00:13:46 | C | 540 | 19.0 | Coadd 108618 | 2019-08-16 03:20:57 | C | 1080 | 19.3 | Coadd ~5 days| 2019-08-20 21:00:43 | C | 540 | 20.1 | Coadd ~6 days| 2019-08-21 19:55:47 | C | 540 | 20.7 | Coadd We see host galaxy and OT on some images. For example Robot find MASTER OT J005332.32-234958.5 at 23 Aug: Date RA Dec Tube OT mag unfiltered 2019-08-23 02:45:31.4 00h 53m 32.32s, -23d 49m 58.48s W 20.1 However, the object is visible at the limit and therefore reduction is continuated. The Alert page is availabl at https://master.sai.msu.ru/site/master2/ligo_1.php?id=10685&nb=1 This message can be cited. [GCN OPS NOTE(26aug19): Per author's request, the "LIGO/Virgo" prefix was added to the Subject line.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25477 SUBJECT: LIGO/Virgo S190814bv: LCO Photometry of DG19wxnjc/AT2019npv DATE: 19/08/26 04:30:11 GMT FROM: Michael Coughlin at Caltech/LIGO Michael Coughlin, Tomas Ahumada, and Shreya Anand report on behalf of Global Relay of Observatories Watching Transients Happen (GROWTH): We observed the transient DG19wxnjc/AT2019npv (Goldstein et al. GCN 25393) with the Siding Springs 2m Spectral imager of Las Cumbres Observatory (LCO) on 2019-08-22 from 16:31:28 UTC to 16:41:30 UTC and on 2019-08-24 from 19:11:45 UTC to 19:27:47 UTC. On the first night, we report non-detection upper limits of g > 21.3 +/- 0.1, r > 21.2 +/- 0.1, and i > 21.1 +/- 0.1 with 180 s exposures in all three filters. Our second night of observations yielded detections of the transient with 300 s exposures in all three filters. Using references from the DECam Legacy Survey (DECaLS), we performed image differencing of our night 2 epochs and report photometry estimates of i = 21.9 +/- 0.2 and r = 22.5 +/- 0.2, with a low significance detection in g-band, g ~< 23. We caution that we used an average of r-band and z-band DECaLS templates to perform image subtraction for the i-band image due to the unavailability of i-band references with DECaLS, making it difficult to make confident statements about the i-band evolution of the transient. We encourage further photometric follow-up, and more observations are planned. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25478 SUBJECT: LIGO/Virgo S190814bv: Keck II NIRES classification of DG19wxnjc/AT2019npv as a stripped envelope supernova DATE: 19/08/26 06:52:50 GMT FROM: Kishalay De at Caltech, GROWTH K. De, J. Jencson, M. M. Kasliwal, D. Goldstein, I. Andreoni (Caltech) report on behalf of the GROWTH (Global Relay of Observatories Watching Transients Happen) collaboration We further optimized the reduction of the Keck II NIRES spectrum of DG19wxnjc/AT2019npv (Goldstein et al. GCN 25393) reported earlier in De et al. GCN 25461. With better telluric correction, the He I 10830 line reported in our previous GCN is now more clearly identifiable with a P-Cygni profile at z=0.056 (Jonker et al. GCN 25454) and velocity of approximately 9000 km/s. This would be consistent with a stripped envelope supernova and thus, unrelated to LIGO/Virgo S190814bv (LVC et al. GCN 25324, GCN 25333). However, the observed faint luminosity of -15.75 mag (Annis et al. GCN 25458) suggests there could have been a brighter peak before discovery. We are grateful to the W. M. Keck Observatory staff, especially Greg Doppmann and Terry Stickel, for facilitating this partnership target of opportunity observation. We thank the observer Leslie Young for her kind co-operation. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25480 SUBJECT: LIGO/Virgo S190814bv: Radio non-detection of DG19wxnjc/AT2019npv with the VLA DATE: 19/08/26 17:25:09 GMT FROM: Kishalay De at Caltech, GROWTH Kunal Mooley (NRAO, Caltech), Gregg Hallinan, Mansi Kasliwal (Caltech), Alessandra Corsi (TTU), Dale Frail (NRAO) report on behalf of the JAGWAR collaboration We observed the location of DG19wxnjc/AT2019npv (GCN 25393) on 2019 August 24 with the VLA at C band. No radio emission from AT2019npv is detected, and we report a 3sigma upper limit of about 12 uJy on the 6 GHz flux density. We thank the NRAO staff for the quick scheduling of this observation and help with obtaining the data. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25481 SUBJECT: LIGO/Virgo S190814bv: SALT optical spectrum of candidate DG19aqbkc DATE: 19/08/26 20:23:14 GMT FROM: Marina Orio at INAF-Padova and U of Wisconsin David Buckley, (South Africa Astronomical Observatory, South Africa), Stefano Ciroi (University of Padova, Department of Physics and Astronomy, Italy), Mariusz Gromadzski (University of Warsaw, Astronomical Observatory, Poland), Mansi Kasliwal (Cahill Center for Astronomy and Astrophysics, Caltech, Pasadena, CA, USA), Marina Orio (INAF-Padova Observatory, Italy, and Department of Astronomy, University of Wisconsin-Madison, USA), Jeff Cooke (Australian Research Council Center of Exellence for Gravitational Wave Discovery, Swinburne University of Technology, Australia) , Saurabh Jha (Department of Physics and Astronomy, Rutgers University, NJ, USA) and Moses Mogotsi (SALT, South Africa Astronomical Observatory, South Africa), report: We obtained an optical spectrum of the transient source DG19aqbkc/AT2019nqc (Andreoni et al. GCN 25362), identified as one possible electromagnetic counterpart of the the gravitational wave event S190814bv (LVC et al. GCN 25324, GCN 25333) by the DECam GROWTH team. The spectrum, obtained with the Robert Stobie spectrograph on the SALT telescope and the PG 300 grating, in the 3300-9800 Angstrom range with a 22 Angstrom spectral resolution, is consistent with a type II supernova two weeks after optical maximum. The redshift is approximately 0.077. The classification was obtained using SNID (Blondin & Tonry 2007). We measured a broad H-alpha line with a P-Cygni profile and an weak H-beta line in absorption. This result appears to rule out this transient as an optical counterpart of the gravitational wave event. [GCN OS NOTE(27aug19): Per author's request and administrator: The event reference was changed from "S190814b" to "S190814bv". And the SUBJECT-line was changed to "LIGO/Virgo S190814bv: SALT optical spectrum of candidate DG19aqbkc", and the in-body TITLE- & SUBJECT-lines were removed.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25483 SUBJECT: LIGO/Virgo S190814bv : Magellan IMACS Spectrum of AT2019npv classified as a Type Ib supernova DATE: 19/08/27 03:33:34 GMT FROM: Sebastian Gomez at Harvard U S. Gomez, G. Hosseinzadeh, E. Berger, P. K. Blanchard, T. Eftekhari, J. Gill, L. Patton, V. A. Villar, P. K. G. Williams (Harvard U), P. S. Cowperthwaite (Carnegie Obs), R. Chornock (Ohio U), W. Fong, R. Margutti, K. D. Alexander (Northwestern U), and M. Nicholl (U Edinburgh) report: We observed AT2019npv (Goldstein et al. GCN 25393) with the IMACS optical spectrograph on the Magellan 6.5m telescope (Dressler et al. 2011) on 2019 Aug 26 09:26:09UT. We corroborate the redshift measurement of z = 0.056 from Jonker et al. (GCN 25454) and De. et al. (GCN 25480, 25461) by measuring the location of prominent host emision lines. We see mainly emision lines of Ca II 7291, 7323, O I 6300, and He I 5876. Leading to the classification of this transient as a Type Ib supernova, and therefore unrelated to the LIGO event S190814bv (GCN 25324, GCN 25333). We find a best match to a supernova ~50 days after peak using template matching with SNID (Blondin & Tonry, 2007, ApJ, 666, 1024). We thank Dave Osip for taking these observations at Magellan. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25484 SUBJECT: LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019npw and AT2019num DATE: 19/08/27 07:50:35 GMT FROM: Douglas Tucker at Fermilab LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019npw and AT2019num Douglas Tucker (Fermilab), Melissa Butner (ETSU), Matt Wiesner (Benedictine U), Ósmar Rodríguez (UNAB), Nicolás Meza-Retamal (ESO Chile), Jonathan Quirola (PUC), Felipe Olivares (INCT/UDA), Sean Points (NOAO/CTIO), Regis Cartier (NOAO/CTIO), Sahar Allam (Fermilab), Marcelle Soares-Santos (Brandeis U), Clara Martinez-Vazquez (NOAO/CTIO), Alyssa Garcia (Brandeis U), Ken Herner (Fermilab), James Annis (Fermilab), Martin Makler (CBPF), Antonella Palmese (Fermilab), Nora Sherman (Fermilab and Brandeis U), Robert Morgan (U of Wisconsin-Madison), Tristan Bachmann (U Chicago), Tamara Davis (U Queensland), Kristen Dage (MSU), Adam Kawash (MSU), Jay Strader (MSU), Laura Chomiuk (MSU) On behalf of the DESGW team*: We report SOAR Goodman spectroscopy of AT2019npw and AT2019num, possible counterparts to the black hole-neutron star merger S190814bv reported by the GROWTH team (GCN Circulars No. GCN 25362, 25393, 25394) based on data obtained by the DESGW team using the CTIO Blanco/DECam instrument. We obtained a 45 min exposure of 2019npw and a 10 min exposure of 2019num using the Goodman instrument on the 4.1m SOAR telescope at Cerro Pachón. The analysis of these spectra allow us to conclude that both candidates are unrelated to the merger: 2019npw is consistent with a type IIb supernova at redshift 0.163 2019num is consistent with a type IIP supernova at redshift 0.113 The SOAR followup program is a partnership between the US (PIs: Kilpatrick & Tucker), Chilean (PI: Olivares), and Brazilian (PI: Makler) community. The optical counterpart was identified by the DECam Search & Discovery Program for Optical Signatures of Gravitational Wave Events (DESGW, PI: Soares-Santos), which is carried out by the Dark Energy Survey (DES) collaboration in partnership with wide ranging groups in the community. DESGW uses data obtained with the Dark Energy Camera (DECam), which was constructed by the DES collaboration with support from the Department of Energy and member institutions, and utilizes data as distributed by the Science Data Archive at NOAO. NOAO is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes do Brasil (MCTIC/LNA), the U.S. National Science Foundation's National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). *The DESGW Collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner (ETSU), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soar es-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25485 SUBJECT: LIGO/Virgo S190814bv: CFHTphotometryof AT2019npv DATE: 19/08/27 08:05:00 GMT FROM: Xiaofeng Wang at Tsinghua University X. Wang (THU), S. Antier (APC), M. Coughlin (Caltech), W. Li (THU), X. Zhang (THU), J. Mo (THU), G. Xi (THU), J. Bai (Yunnan Obs), S. Basa (LAM), E. Bertin (IAP), M. Blazek (HETH/IAA-CSIC), Michel Boer (Artemis), A. Coleiro (APC), N. Christensen (Artemis), S. Ehgamberdiev (UBAI), D. A. Kann (HETH/IAA-CSIC), A. Klotz (IRAP), D. Coward (OzGrav-UWA), D. Corre (LL), J.G. Ducoin (LAL), B. Gendre (OzGrav-UWA), P. Hello (LAL), L. Hu (PMO), C. Lachaud (APC), X. Jiang (NAOC), N. Leroy (LAL), B. Li (PMO), W. Lin (THU), D. Mirzaqulov (UBAI), T. Sun (PMO), C. Thoene (HETH/IAA-CSIC), D. Turpin (NAOC), L. Wang (Texas University/PMO), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), X. Wu (PMO), H. Zhao (PMO), X. Zeng (XAO), J. J. Zhang (YNAO), J. C. Zhang (THU): Report on behalf of AOGOT (All-sky Observations of Gravitational Optical Transients) and Grandma joint collaborations: Using the MegaPrime/MegaCam instrument (1x1 deg FOV) at the Canada-France-Hawaii Telescope, we observed the candidate AT2019npv reported by Goldstein et al (GCN 25393) close to a galaxy at z=0.056 (Jonker et al, GCN 25454), which was a candidate electromagnetic counterpart of the GW event S190814bv (LIGO/Virgo Collaboration, GCN 25324, GCN. 25333). Multiple images were obtained with the CFHT for this object in g(210sx2), r(240sx2) and i(300sx2) bands beginning at 2019-08-24 13:08 UTC. Using references from the DECam Legacy Survey (DECaLS), we performed image differencing in g and r-bands, with a low significance detection in g-band and an r-band estimate of r_AB = 23.0+-0.05 mag (i-band has a significant detection, but the reference is not available and therefore the numbers are unreliable). This object has been ruled out by different spectroscopic observations and photometric archival analysis as being related to the LIGO/Virgo GW candidate (GCN25468, GCN25475, GCN25478). GCN OPS NOTE(27aug19): Per author's request, the last reference in the last sentence was changed from "GCN5478" to "GCN25478"; and C. Corre was added to the author list.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25486 SUBJECT: LIGO/Virgo S190814bv: Final list of candidates from the DESGW coadd analysis from the week long search campaign DATE: 19/08/27 08:22:13 GMT FROM: M. Soares-Santos at Fermi Lab Marcelle Soares-Santos, James Annis, Ken Herner, Antonella Palmese, Alyssa Garcia, Douglas Tucker, Sahar Allam, Robert Morgan, Tristan Bachmann, Nora Sherman, Alfredo Zenteno, Kathy Vivas, Clara Martinez, Tamara Davis, Melissa Butner, Matt Wiesner, Luidhy Santana, Ósmar Rodríguez, Felipe Olivares, Nicolas meza retamal, Jonathan Quirola, Sean Points, Regis Cartier, Chris Lidman, Umang Malik, Andre Luiz Figueiredo, Jhon Joel Yana Galar *On behalf of the DESGW Team We present our assessment of transients from our 5 nights of DECam/Blanco data. We find 23 candidate counterparts, 18 of which are new reports to the GCN. This is a complete catalog of candidates from our data. We provide a ranking of candidates based on detection images, light curves and host galaxy properties to allow workers to prioritize observations. Our reading of the GCN archive suggests this note discusses all remaining viable candidates. The black hole/neutron star merger S190814bv reported by the LIGO/VIRGO Collaboration (GCN Circular No. 25324, and updated GCN Circular No. 25333) has a sky localization inside the DES footprint. The DESGW collaboration used the DECam on the CTIO Blanco telescope to image the region of interest five nights within one week of the merger (20190814, 20190815, 20190816, 20190817, 20190820). Each night we obtained several i & z band images of an area containing 92% of the spatial localization, with images of the same place on the sky separated by either ~30 to 60 minutes. The individual images have 10 sigma PSF limiting magnitudes of i: 19.8 to 22.7 with median=21.4; z: 19.3 to 22.2 with median=21.5, depending on conditions, which were poor (full moon, clouds, poor seeing) the first few nights but improved over time. The data were immediately made public. In the DESGW reduction, we coadd all images from a given night, bandpass, & location to improve S/N. Images were processed by our difference imaging pipeline (Herner et al. 2017; see also Soares-Santos et al. 2015, 2017; Doctor et al. 2018; Morgan et al. 2019 for recent applications) using DES images as templates. The initial list of difference objects were through a machine learning code (Goldstein et al. 2015) to reject subtraction artifacts. Candidates were selected from the new list by requiring >=2 high S/N detections, rejecting asteroids and many spurious objects. We then subjected the candidate list to a vetting process. We reject variable stars and quasars via identification of pre-existing stellar objects in the template images as well as matching against GAIA DR2 and the MILLIQUAS catalog. Asteroids are rejected by our 2 images per night observing strategy and by matching against the Minor Planet Center. The final vetting step was a human inspection of every remaining candidate’s difference image stamps, rejecting any remaining bad subtractions. The remaining candidates, 23 in all, make up the full catalog of candidates by DESGW on this event. The table below is ordered from highest priority to lowest. PRI is a discretized ranking showing grouping of similar priorities and hence our confidence that the transient is related to S190814bv. Table 1: Candidates NAME | INTERNAL_NAME | RA | DEC | MJD | MAG | BAND | PRI 2019omt | desgw-190814v | 14.8614 | -25.9948 | 58716.220 | 22.9 | z | 1 2019onj | desgw-190814ab | 11.8584 | -25.4486 | 58716.182 | 22.4 | z | 1 2019odc | desgw-190814r | 11.5070 | -25.4592 | 58716.234 | 22.6 | i | 1 2019omw | desgw-190814y | 12.2344 | -23.1701 | 58716.212 | 22.8 | i | 1 2019nzr | desgw-190814m | 11.8392 | -24.5768 | 58716.234 | 22.9 | z | 1 2019ntr | DG19sbzkc | 15.0078 | -26.7143 | 58716.198 | 21.4 | z | 1 2019nxd | desgw-190814i | 10.6858 | -24.9556 | 58716.234 | 22.5 | i | 1 2019ntm | DG19jqzkc | 12.0184 | -23.7975 | 58716.177 | 21.7 | z | 2 2019omx | desgw-190814z | 24.1844 | -33.3027 | 58716.230 | 22.1 | z | 2 2019obc | desgw-190814q | 14.5667 | -24.1397 | 58716.193 | 21.8 | z | 2 2019ntp | DG19gcwjc | 12.5503 | -26.1979 | 58716.182 | 21.3 | z | 2 2019nuq | DG19kxdnc | 11.1440 | -22.0291 | 58716.209 | 23.4 | z | 2 2019nte | desgw-190814f | 23.5574 | -31.7217 | 58716.223 | 22.4 | i | 2 2019oac | DG19zujoc | 13.2621 | -21.6513 | 58716.214 | 21.6 | z | 2 2019nzd | DG19kzvqc | 14.5269 | -24.8373 | 58716.220 | 22.5 | z | 3 2019omu | desgw-190814w | 23.4954 | -34.3389 | 58716.230 | 22.4 | z | 3 2019omv | desgw-190814x | 24.9784 | -33.3837 | 58716.230 | 22.6 | z | 3 2019nys | desgw-190814k | 14.4871 | -24.5668 | 58716.220 | 22.2 | z | 3 2019opp | desgw-190814ac | 14.4094 | -25.2792 | 58716.220 | 22.3 | z | 3 2019oks | desgw-190814u | 15.5347 | -24.9060 | 58716.220 | 22.5 | z | 3 2019okr | desgw-190814t | 11.8487 | -25.4585 | 58716.234 | 22.1 | i | 3 2019nxe | desgw-190814j | 11.5701 | -24.3726 | 58716.177 | 22.4 | z | 3 2019oab | desgw-190814o | 14.7475 | -25.7702 | 58716.220 | 23.2 | z | 3 All magnitudes reported are observed magnitudes. The MJD is the date of observation. We encourage spectroscopic followup of these candidates. In order to help plan followup strategies, we provide a table with information related to our prioritization. In particular, we provide each candidate’s host galaxy, including how far away their redshifts are from S1901814bv’s distance (NSIG). We noticed during visual inspection that a few candidates reside within a few arcseconds of their host’s nucleus. Our analysis does not support accurate detection of a counterpart on top of an AGN, so we use the DES data to flag candidates that are close to the center of a galaxy with AGN-like colors. We also provide the probability of each transient’s evolution being consistent with a non-flat light curve (LC) and the LVC localization probability covered by the exposure in which that candidate was detected (GWPROB). Table 2: Host galaxies and other information NAME | HOST | Z | ZERR | NSIG | SEP | AGN | LC | GWPROB 2019omt | GALEXMSC J005926.52-255943.1 | 0.07 | 0.09 | 0.1 | 2.3 | 0 | 0.95 | 0.68 2019onj | GALEXASC J004724.99-252657.2 | 0.68 | 0.29 | 2.1 | 12.4 | 0 | 0.66 | 2.81 2019odc | 2MASS J00460172-2527330 | 0.08 | 0.02 | 1.2 | 2.0 | 1 | 1.00 | 12.73 2019omw | DES J004855.43-231011.4 | 0.68 | 0.36 | 1.7 | 11.4 | 0 | 0.75 | 1.29 2019nzr | MRSS 474-057474 | 0.17 | 0.18 | 0.6 | 1.0 | 1 | 1.00 | 7.47 2019ntr | DES J010001.73-264252.6 | 0.19 | 0.12 | 1.1 | 2.7 | 0 | 0.91 | 0.55 2019nxd | DES J004245.24-245716.88 | 1.34 | 0.49 | 2.6 | 9.5 | 0 | 0.83 | 0.27 2019ntm | MRSS 474-053630 | 0.51 | 0.20 | 2.3 | 0.7 | 1 | 0.83 | 5.90 2019omx | DES J013644.21-331810.1 | 0.59 | 0.28 | 1.9 | 0.6 | 0 | 0.83 | 2.30 2019obc | DES J005815.91-240823.4 | 0.28 | 0.18 | 1.2 | 1.5 | 0 | 0.79 | 0.57 2019ntp | GALEXASC J005012.14-261153.4 | 0.18 | 0.04 | 2.8 | 1.2 | 0 | 0.45 | 2.79 2019nuq | | | | | | 1 | 0.65 | 1.03 2019nte | GALEXASC J013413.83-314318.3 | 0.07 | 0.00 | 1.0 | 0.6 | 1 | 0.66 | 0.60 2019oac | 2MASS J00530289-2139035 | 0.14 | 0.02 | 4.0 | 1.6 | 0 | 0.75 | 0.22 2019nzd | DES J005806.51-245015.7 | 0.43 | 0.15 | 2.5 | 1.6 | 0 | 0.35 | 0.21 2019omu | GALEXASC J013358.90-342020.7 | 0.66 | 0.03 | 22.1 | 1.7 | 0 | 0.53 | 0.65 2019omv | DES J013954.76-332300.4 | 0.36 | 0.02 | 11.5 | 1.2 | 0 | 0.54 | 0.33 2019nys | DES J005756.95-243400.6 | 0.41 | 0.06 | 5.9 | 0.7 | 1 | 0.56 | 0.35 2019opp | DES J005738.22-251645.6 | 0.42 | 0.07 | 5.1 | 0.7 | 1 | 0.67 | 0.24 2019oks | DES J010208.25-245422.0 | 0.13 | 0.10 | 0.7 | 0.9 | 1 | 0.54 | 0.02 2019okr | | | | | | 0 | 0.38 | 0.01 2019nxe | APMUKS(BJ) B004349.14-243846.0 | 0.21 | 0.21 | 0.7 | 2.5 | 0 | 0.49 | 0.00 2019oab | DES J005859.33-254612.8 | 0.53 | 0.19 | 2.4 | 0.2 | 1 | 0.38 | 0.00 In the table above, Z and ZERR are the host redshift and its uncertainty, from the DES photometric redshift catalog. In the few cases where a spectroscopic redshift is publicly available, we provide that instead of photometric estimates. SEP is the candidate to host galaxy separation, in arcseconds. AGN denotes where a PSF magnitude of the host galaxy has DES colors consistent with DES PSF colors of the MILLIQUAS AGN in the DES footprint. Prior to this report, the GCN archive contained 12 viable candidates, all from DECam data. Five of them pass our selection process and are included in the list above: AT2019obc, AT2019nte, AT2019ntp, AT2019ntr, AT2019nuq. The following 7 previously reported candidates fail our quality criteria: AT2019nqz, AT2019nsm, AT2019nts, AT2019nuj, AT2019nuk, AT2019nul, AT2019nun. We suggest that these are unrelated to S190814bv. Spectroscopic followup is required to confidently confirm or reject the association of the remaining viable candidates with the black hole-neutron star merger event discovered by the LVC. The DECam Search & Discovery Program for Optical Signatures of Gravitational Wave Events (DESGW) is carried out by the Dark Energy Survey (DES) collaboration in partnership with wide ranging groups in the community. DESGW uses data obtained with the Dark Energy Camera (DECam), which was constructed by the DES collaboration with support from the Department of Energy and member institutions, and utilizes data as distributed by the Science Data Archive at NOAO. NOAO is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. *The DESGW Collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner, (Fermilab), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25487 SUBJECT: LIGO/Virgo S190814bv: Detection of a candidate radio counterpart with ASKAP DATE: 19/08/27 08:23:52 GMT FROM: Dougal Dobie at VAST Adam Stewart (University of Sydney), Dougal Dobie (University of Sydney/CSIRO), Tara Murphy (University of Sydney), Emil Lenc (CSIRO), Ziteng Wang (University of Sydney), David Kaplan (UWM), Aidan Hotan (CSIRO), Vanessa Moss (CSIRO) and the OzGrav, JAGWAR and GROWTH collaborations. We report the discovery of a rising radio source detected with the Australian Square Kilometre Array Pathfinder (ASKAP) within the 95% localisation volume of S190814bv (GCN 25324). The observations were conducted at a frequency of 943 MHz on 2019-08-16 and 2019-08-23 (see GCN 25445 and GCN 25472 for details). We searched for sources with a rising flux density between the two observations that are spatially coincident with known galaxies selected from the GLADE catalogue (Dálya et al. 2018). One candidate is ASKAP 005547-270433, reported as AT2019osy on the Transient Name Server, at RA = 00:55:47, Dec = -27:04:33, offset ~1 arcsecond from 2dFGRS TGS211Z177. ASKAP 005547-270433 has a 943 MHz integrated flux density of 376 +/- 33 uJy in epoch 1 and 550 +/- 34 uJy in epoch 2. The redshift of 2dFGRS TGS211Z177 is 0.0738, which is consistent with the luminosity distance of S190814bv (270+/-50 Mpc, GCN 25324). Further analysis of these ASKAP observations are ongoing and future epochs are planned. Thank you to CSIRO staff for supporting these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25488 SUBJECT: LIGO/Virgo S190814bv: DECam-GROWTH detection of an optical counterpart to the radio source AT2019osy DATE: 19/08/27 08:32:18 GMT FROM: Igor Andreoni at Caltech Igor Andreoni (Caltech), Danny Goldstein (Caltech), Dougal Dobie (University of Sydney/CSIRO), Mansi M. Kasliwal (Caltech) report on behalf of the GROWTH (Global Relay of Observatories Watching Transients Happen) collaboration We report the discovery of an optical transient spatially coincident with AT2019osy (Stewart et al., GCN #25487), a rising radio source identified with ASKAP during the follow-up of the gravitational wave event S190814bv (GCN #25324). The optical transient was automatically detected in public data obtained by the DESGW team (GCN #25336, GCN #25360, GCN #25373, GCN #25398) during the follow-up of S190814bv under the NOAO target of opportunity program 2019B-0372 (PI Soares-Santos). The data were processed using the image subtraction pipelines described in Goldstein, Andreoni et al. (2019) and Andreoni, Goldstein et al. (2019). On the last night of DECam observations (MJD 58716.26) the optical transient was detected at preliminary magnitude i=22.3. GROWTH is a worldwide collaboration comprising of Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, UK; TTU, USA; USyd, Australia; and SDSU, USA. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. We gratefully acknowledge Amazon, Inc. for a generous grant that funded our use of the Amazon Web Services cloud computing infrastructure to process the DECam data. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25492 SUBJECT: LIGO/Virgo S190814bv: Optical non-detection of radio source AT2019osy from CFHT DATE: 19/08/27 16:41:04 GMT FROM: John J. Ruan at McGill U J. Ruan (McGill U.), N. Vieira (McGill U.), D. Haggard (McGill U.), M. R. Drout (U. of Toronto), N. Asfari (U. of Toronto), R. Carlberg (U. of Toronto), R. Doyon (U. de Montreal), R. Fernandez (U. of Alberta), B. Gaensler (U. of Toronto), D. Lafreniere (U. de Montreal), C. Matzner (U. of Toronto), D-S. Moon (U. of Toronto), C. Ni (U. of Toronto), M. Nynka (MIT), A. L. Piro (Carnegie Obs.), S. Safi-Harb (U. of Manitoba), K. Spekkens (RMC/Queen's U.) We report upper-limits from our CFHT non-detections of the optical counterpart to AT2019osy, including deep g-band imaging within a few hours of the DECam detection. AT2019osy was originally reported as a rising radio source in ASKAP observations (GCN 25487), lying within the 95% localization volume of LIGO/Virgo S190814bv (GCN 25333). An optical counterpart was subsequently reported in DECam observations at MJD 5816.26 (GCN 25488), with a preliminary magnitude of i=22.3. Previously, we used the MegaPrime/MegaCam instrument on CFHT to tile the localization region of LIGO/Virgo S190814bv. Our imaging covered AT2019osy multiple times, including deep g-band observations within hours of the DECam observations that discovered the optical counterpart with i=22.3 mag on MJD 58716. We do not detect AT2019osy in our images, and report the following upper limits: MJD, days post-merger, band, mag 58711.5, 1.7 days, g, >21.85 58713.5, 3.6 days, i, >22.50 58716.5, 6.6 days, g, >23.50 We thank the CFHT queued service observing team and the telescope staff for their help in obtaining these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25494 SUBJECT: LIGO/Virgo S190814bv: Palomar 200-in spectroscopic redshift and host galaxy properties of ASKAP source AT2019osy DATE: 19/08/27 20:05:29 GMT FROM: Daniel Perley at Liverpool JMU Daniel A. Perley (LJMU), Yashvi Sharma (Caltech), Viraj Karambelkar (Caltech), Igor Andreoni (Caltech), and Mansi M. Kasliwal (Caltech) report on behalf of the GROWTH (Global Relay of Observatories Watching Transients Happen) collaboration We obtained a spectrum of the host galaxy of the reported radio and optical transient AT2019osy (Stewart et al., GCN #25487; Andreoni et al., GCN #25488) using the Double Beam Spectrograph (Oke & Gunn 1982) on the Palomar 200-inch Hale Telescope. The spectrum was reduced using the pyraf-dbsp pipeline (Bellm & Sesar 2016). The spectrum is dominated by red continuum that is likely primarily associated with the host galaxy; no obvious broad features are evident. We identify several narrow emission lines (H-alpha; [NII]6548,6583; [SII]6716,6731; possibly [OII]3727) at a common redshift of 0.0733, consistent within 2-sigma of the LVC distance constraint (LIGO/Virgo collaboration, GCN #25324). H-beta and [OIII]5007 are not detected in the spectrum. The flux ratio of the [NII] and H-alpha lines suggests AGN flux likely contributes to the emission lines, although this assessment is tentative since the line fluxes have not been corrected for any underlying stellar continuum features. Further analysis is ongoing. GROWTH is a worldwide collaboration comprising of Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, UK; TTU, USA; USyd, Australia; and SDSU, USA. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. DisclaimerNone //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25495 SUBJECT: LIGO/Virgo S190814bv: DESGW non-detection of AT2019osy/ASKAP 005547-270433 DATE: 19/08/27 22:14:55 GMT FROM: Ken Herner at Fermi Nat Accelerator Lab LIGO/Virgo S190814bv: DESGW non-detection of AT2019osy/ASKAP 005547-270433 Ken Herner, Marcelle Soares-Santos, James Annis, Antonella Palmese on behalf of the DESGW Team* We cannot confirm the optical detection in DECam data reported by Andreoni et al. in GCN 25488, said to be spatially coincident with AT2019osy/ASKAP 005547-270433 (Stewart et al., GCN 25487). Between MJD 58716.19 and 58716.36 we imaged the candidate area three times in both i and z band. We did not record any detections in our difference imaging pipeline within 3" of the coordinates reported in GCN 25487 (ra,dec = 13.945833,-27.075833) either in the individual images or in the coadded analysis (where we combine images in a given bandpass from the same night; see Soares-Santos et al. GCN 25486). We also did not record any detections at that location in our first four nights of observations. We have a single low-significance detection in one bandpass in the coadded images from MJD 58716.19 to 58716.36, but it does not pass our most basic quality cuts. Also, there is a 3.2" separation between our detection (ra,dec=13.946664, -27.076167) and the transient coordinates in TNS. We visually inspected the DES Year 5 coadded image at the position of ASKAP 005547-270433 (GCN 25487) and there is definitely light from the nearby edge-on dusty spiral galaxy at that location. *The DESGW Collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner, (Fermilab), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25496 SUBJECT: LIGO/Virgo S190814bv: Correction of ASKAP coordinates DATE: 19/08/27 23:27:48 GMT FROM: Dougal Dobie at VAST Adam Stewart (University of Sydney), Dougal Dobie (University of Sydney/CSIRO), and Tara Murphy (University of Sydney) In GCN 25487 the position given for the ASKAP candidate counterpart, AT2019osy, was accidentally truncated. The correct name and position are: ASKAP J005547.4-270433 at RA = 00:55:47.4, Dec = -27:04:33. The typical astrometric uncertainty in this field is 1-2 arcseconds. We apologise for any inconvenience caused. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25525 SUBJECT: LIGO/Virgo S190814bv: Swift UVOT - no new counterpart candidates identified DATE: 19/08/28 18:31:22 GMT FROM: Alice Breeveld at MSSL-UCL A. A. Breeveld (UCL-MSSL), S. R. Oates (U. Warwick), F. E. Marshall (NASA/GSFC), N. P. M. Kuin (UCL-MSSL), M.J. Page (UCL-MSSL), P. Brown (TAMU), C. Gronwall (PSU), M. de Pasquale (Istambul U.), M. H. Siegel (PSU), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB), S. D. Barthelmy (NASA/GSFC), A. P. Beardmore (U. Leicester), D. N. Burrows (PSU), S. Campana (INAF-OAB), S. B. Cenko (NASA/GSFC), G. Cusumano (INAF-IASF PA), V. D'Elia(ASDC), P. A. Evans (U. Leicester), P. Giommi (ASI), D. Hartmann (Clemson U.), J. A. Kennea (PSU), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), D. B. Malesani (DARK/NBI), A. Melandri (INAF-OAB), J. A. Nousek (PSU), P. T. O'Brien (U. Leicester), J. P. Osborne (U. Leicester), C. Pagani (U. Leicester), K. L. Page (U.Leicester), D.M. Palmer (LANL), M. Perri (ASDC), J. L. Racusin (NASA/GSFC), T. Sakamoto (AGU), B. Sbarufatti (INAF-OAB/PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (PSU), and E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team: The Swift UVOT instrument started follow up observations of the LIGO-Virgo event S190814bv (LVC GCN Circ. 25324) 11ks after the trigger following the tiling programme described in Evans et al. (GNC Circ. 25400). The UVOT approach for searching for the ultraviolet-optical counterpart has been described in Kuin et al. (GCN Circ. 24767). The limiting magnitude can vary but typically is 18.6th magnitude (Vega) in the U filter. In the 352 fields that were observed, UVOT detected 98 counterpart candidates and 2257 catalogued galaxies. None of the candidates from the automated processing proved to be a viable candidates. Neither did the additional inspection of all 2257 imaged galaxies lead to a candidate missed by the automated processing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25526 SUBJECT: LIGO/Virgo S190814bv: no variation of DESGW candidates AT 2019onj and AT 2019okr from ENGRAVE VLT/HAWK-I observations, and archival detection DATE: 19/08/28 19:26:10 GMT FROM: Susanna Vergani at INAF/Brera J. Japelj (Univ. of Amsterdam), E. Kankare (Univ. Turku), E. Kool (OKC), A. J. Levan (Radboud Univ.), K. Maguire (Trinity College Dublin), D. B. Malesani (DTU Space), S. Mattila (Univ. Turku), B. Milvang-Jensen (DAWN/NBI), T. Reynolds (Univ. Turku), N.B. Sabha (Univ. Innsbruck), S. D. Vergani (Paris Observatory-CNRS) report on behalf of the ENGRAVE collaboration: ENGRAVE targeted 9 fields containing 17 high-probability host galaxies for S190814bv, based on the LALInference skymap (LIGO Scientific Collaboration and Virgo Collaboration, GCN 25333), with deep VLT/HAWK-I imaging over two epochs in a search for intrinsically faint, near-infrared transient sources. As part of this search, we observed the field of two candidates, AT 2019onj and AT 2019okr, reported by Soares-Santos et al. (GCN 25486). The observations were conducted between 06:55 and 07:14 UT on 2019-08-16 and a second epoch between 04:32 and 04:50 UT on 2019-08-21, approximately 1.4 and 6.3 d after S190814bv, respectively (600 s exposure per epoch in the Ks filter). The sources are detected in both epochs with magnitudes: Name dT Ks mag AT 2019onj 1.4 d 19.20 +- 0.03 AT 2019onj 6.3 d 19.15 +- 0.02 AT 2019okr 1.4 d 19.55 +- 0.03 AT 2019okr 6.3 d 19.54 +- 0.03 The magnitudes (in the Vega system, not corrected for extinction) are based on preliminary photometry calibrated against a single 2MASS star, and the absolute calibration has an extra error by 0.05 mag. No significant variability can be measured between our HAWK-I observations. This field was also covered serendipitously by the ESO/VISTA survey telescope in the Ks band during its science verification program. Both objects are detected in images from 2009-10-23 and 2009-10-30, and both are fainter than in the HAWK-I images (by 0.68+-0.18 and 0.83 +- 0.26 mag for AT 2019onj and AT 2019okr, respectively). The large uncertainty is entirely due to the low S/N of the archival VISTA data. The lack of variability between the VLT/HAWK-I epochs and especially the archival detections suggest that AT2019onj and AT2019okr are unrelated to S190814bv. We acknowledge the ESO observing staff at Paranal, in particular S. Brillant, J. Corral-Santana, B. Haussler, C. Opitom, F. J. Selman, and T. Szeifert. Based on observations collected by the ENGRAVE collaboration at the European Southern Observatory under ESO program 0103.D-0722 (for further information on ENGRAVE see http://www.engrave-eso.org/). The VISTA data were secured under science verification program 60.A-9285(A). We acknowledge valuable help with the archival VISTA data by Carlos Gonzalez-Fernandez (CASU / IoA Cambridge). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25539 SUBJECT: LIGO/Virgo S190814bv: VLA observation of ASKAP J005547-270433/AT2019osy DATE: 19/08/29 07:33:40 GMT FROM: Kunal Mooley at NRAO,Caltech Kunal Mooley (NRAO, Caltech), Gregg Hallinan (Caltech), Dale Frail (NRAO), Alessandra Corsi (TTU), Kenta Hotokezaka (Princeton), Mansi Kasliwal (Caltech), Dougal Dobie (U. Sydney, CSIRO), Tara Murphy (U. Sydney), David Kaplan (UWM) report on behalf of the JAGWAR collaboration We observed ASKAP J005547-270433 (GCN 25487) with the VLA between 1-12 GHz on 2019 Aug 28.3. We find that the spectrum between the observed frequencies is consistent with a single power law. The derived spectral index is -0.42, and the extrapolated 943 MHz flux density is 490+/-20 uJy (compare with 550+/-34 uJy from ASKAP Aug 23). The radio source appears to be unresolved on 100 mas scales, and its coordinates are consistent with the optical centroid (obtained from DECaLS DR8) of 2dFGRS TGS211Z177 to 0.1 arcsec. The 3 GHz luminosity is 3e28 erg/s/Hz, assuming association with the 2dFGRS galaxy. The radio spectral index, source position and size, and luminosity of ASKAP J0055-27 are consistent with a low luminosity AGN, and variability observed by ASKAP consistent with refractive interstellar scintillation. Although a radio AGN is the likely explanation, we cannot completely rule out the association of ASKAP J0055-27 with S190814bv. The radio spectrum is rather hard for a merger afterglow (implying the electron power-law index p to be <2), however additional epochs are encouraged to separate any possible afterglow component from AGN scintillation. We thank the NRAO staff for scheduling the VLA observation. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25540 SUBJECT: LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019ntr and AT2019omx DATE: 19/08/29 08:01:11 GMT FROM: Douglas Tucker at Fermilab LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019ntr and AT2019omx Matt Wiesner (Benedictine U), Melissa Butner (ETSU), Douglas Tucker (Fermilab), Ósmar Rodríguez (UNAB), Nicolás Meza-Retamal (ESO Chile), Jonathan Quirola (PUC), Felipe Olivares (INCT/UDA), Regis Cartier (NOAO/CTIO), Sean Points (NOAO/CTIO), Sahar Allam (Fermilab), Marcelle Soares-Santos (Brandeis U), Clara Martinez-Vazquez (NOAO/CTIO), Alyssa Garcia (Brandeis U), Ken Herner (Fermilab), James Annis (Fermilab), Antonella Palmese (Fermilab), Nora Sherman (Fermilab and Brandeis U), Robert Morgan (U of Wisconsin-Madison), Tristan Bachmann (U Chicago), Tamara Davis (U Queensland), Ana Carolina de Souza Feliciano (ON) On behalf of the DESGW team*: We report SOAR Goodman spectroscopy of AT2019ntr and AT2019omx, possible counterparts to the black hole-neutron star merger S190814bv reported by the GROWTH team (GCN Circular No. GCN 25393) and our team (GCN Circular No. GCN 25486) based on data obtained by the DESGW team using the CTIO Blanco/DECam instrument. We obtained a 45 min exposure of 2019ntr and a 4 min exposure of the galaxy associated with 2019omx using the Goodman instrument on the 4.1m SOAR telescope at Cerro Pachón. The analysis of these spectra allow us to conclude that 2019ntr is unrelated to the merger: 2019ntr appears to be consistent with a Type II-L supernova at a redshift of about 0.2 (based on running the observed spectrum through the astrodash SN classification software package). We also report a redshift for the host galaxy of 2019omx of 0.275 (based on assuming a strong emission line at 8370 Angstroms is H-alpha). The SOAR followup program is a partnership between the US (PIs: Kilpatrick & Tucker), Chilean (PI: Olivares), and Brazilian (PI: Makler) community. The candidates were identified in data taken by the DECam Search & Discovery Program for Optical Signatures of Gravitational Wave Events (DESGW, PI: Soares-Santos), which is carried out by the Dark Energy Survey (DES) collaboration in partnership with wide ranging groups in the community. DESGW uses data obtained with the Dark Energy Camera (DECam), which was constructed by the DES collaboration with support from the Department of Energy and member institutions, and utilizes data as distributed by the Science Data Archive at NOAO. NOAO is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes do Brasil (MCTIC/LNA), the U.S. National Science Foundation's National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). *The DESGW Collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner (ETSU), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25543 SUBJECT: LIGO/Virgo S190814bv: AT2019nxe and AT2019obc 10.4m GTC spectroscopy DATE: 19/08/29 12:19:30 GMT FROM: Alberto J. Castro-Tirado at IAA-CSIC A. J. Castro-Tirado (IAA-CSIC), A. F. Valeev (SAO-RAS), Y.-D. Hu (IAA-CSIC), E. Fernandez-Garcia (IAA-CSIC), V. V. Sokolov (SAO-RAS), I. Carrasco and A. Castellon (UMA), D. L. Tucker (Fermilab), M. Soares-Santos (Brandeis U) and S. Geier (GRANTECAN, IAC, ULL), on behalf of a larger collaboration, report: Following the detection of desgw-190814j (AT2019nxe) (Soares-Santos et al., GCNC 25425) and desgw-190814q (AT2019obc) (Soares-Santos et al., GCNC 25438 ) within the error area of the GW event S190814bv (LVC, GCNC 25324), we obtained imaging and optical spectra covering the range 5100-10000 A with the 10.4m GTC telescope equipped with OSIRIS in La Palma (Spain) starting on Aug 23, 02:10 UT. AT2019nxe is located 1.8 arcsec away from the center of the host galaxy and on Aug 23, 02:15 UT the magnitude was measured to be r = 20.39 +/- 0.07. The spectrum (broad lines) is consistent with a SNIa near the maximum at the nearby host galaxy redshift (z = 0.0777 +/- 0.0005, based on the narrow emission lines from the galaxy). AT2019obc is located 1.8 arcsec away from the center of the host galaxy. Cross- correlating the spectrum (broad lines) with supernova template spectra in SNID (Blondin & Tonry, 2007), we find a good match to the spectra of SNIa at few days post maximum at a redshift of 0.216 +/- 0.005. Therefore we consider that both AT2019nxe and AT2019obc are unrelated to the GW event S190814bv. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25545 SUBJECT: LIGO/Virgo S190814bv: Swift observation of ASKAP J005547-270433/AT2019osy DATE: 19/08/29 13:12:01 GMT FROM: Sergio Campana at INAF-OAB P. A. Evans (U. Leicester), J. A. Kennea (PSU), A. Tohuvavohu (PSU), S. D. Barthelmy (NASA/GSFC), A. P. Beardmore (U. Leicester), M. G. Bernardini (INAF-OAB), A. A. Breeveld (MSSL-UCL), P. Brown (TAMU), D. N. Burrows (PSU), S. Campana (INAF-OAB), S. B. Cenko (NASA/GSFC), G. Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB), V. D'Elia (ASI-SSDC), S. Emery (UCL-MSSL), P. Giommi (ASI), C. Gronwall (PSU), D. Hartmann (Clemson U.), N. J. Klingler (PSU), H. A. Krimm (NSF), N. P. M. Kuin (UCL-MSSL), A. Y. Lien (GSFC/UMBC), D. B. Malesani (DTU Space), F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), J. A. Nousek (PSU), S. R. Oates (Uni. of Warwick), P. T. O'Brien (U. Leicester), J. P. Osborne (U. Leicester), C. Pagani (U. Leicester), K. L. Page (U.Leicester), M. J. Page (UCL-MSSL), D. M. Palmer (LANL), M. Perri (ASI-SSDC), J. L. Racusin (NASA/GSFC), T. Sakamoto (AGU), B. Sbarufatti (INAF-OAB/PSU), M. H. Siegel (PSU), G. Tagliaferri (INAF-OAB), E. Troja (NASA/GSFC/UMCP), report on behalf of the Swift team: We observed the field of ASKAP J005547-270433/AT2019osy (Stewart et al. GCN 25487) with the Neil Gehrels Swift observatory on August 27 and 28, 2019. The total exposure with the XRT is 4746 s. The source is not detected with an upper limit on the count rate of 1.96e-3 count/s. At a scale distance of 330 Mpc (Perley et al. GCN 25494), this results in an upper limit on the 0.3-10 keV unabsorbed luminosity of ~8e41 erg/s. The UVOT observed the field with the u filter. The total exposure is 4667 s. We clearly detect the galaxy 2dFGRS TGS211Z177 as a slightly extended source at an u(AB) magnitude of 21.08+/-0.09 (5 arcsec aperture). No other sources are apparent in the close proximity of the galaxy. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25557 SUBJECT: LIGO/Virgo S190814bv: Upper limits from a two-week IceCube search for neutrinos from the direction of ASKAP J005547-270433 DATE: 19/08/29 22:02:08 GMT FROM: Alex Pizzuto at ICECUBE/U of Wisconsin The IceCube Collaboration (http://icecube.wisc.edu/) reports: IceCube has performed a search for track-like muon neutrino events arriving from the position of ASKAP J005547-270433 (https://gcn.gsfc.nasa.gov/gcn3/25487.gcn3), a candidate radio counterpart to the LIGO/Virgo event S190814bv (https://gcn.gsfc.nasa.gov/gcn3/25324.gcn3) in the time range of 0.1 days before to 14 days after the gravitational wave trigger time (2019-08-14 18:46:39.010 UTC to 2019-08-28 21:10:39.010 UTC). Two track-like events are found in spatial coincidence with ASKAP J005547-270433 during this time period. These events are consistent (p-value = 1.0) with an atmospheric background-only hypothesis. Accordingly, we derive a time-integrated muon-neutrino flux normalization upper limit assuming an E^-2 spectrum (E^2 dN/dE) at the 90% CL of 4.35 x 10^-4 TeV cm^-2 for this observation period. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc@icecube.wisc.edu. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25571 SUBJECT: LIGO/Virgo S190814bv: AT2019nqc and AT2019nqz 10.4m GTC spectroscopy DATE: 19/08/30 10:44:26 GMT FROM: Alberto J. Castro-Tirado at IAA-CSIC O. Lopez-Cruz (INAOE), A. J. Castro-Tirado (IAA-CSIC), L. Macri (TAMU),A. F. Valeev (SAO-RAS), E. Rios-Lopez (INAOE), Y.-D. Hu (IAA-CSIC), M. Diaz (UTRGV), E. Fernandez-Garcia (IAA-CSIC), E. Troja (UMD), A. Castellon (UMA), Chavushyan (INAOE), D. A. Kann (HETH/IAA-CSIC) and J. Font Serra (GRANTECAN, IAC,ULL), on behalf of three larger collaborations (including TOROS), report: Following the detection of DG19qabkc/AT2019nqc and DG19ayfjc/AT2019nqz (Andreoni et al., GCNC 25362) within the error area of the GW event S190814bv (LVC, GCNC 25324), we obtained imaging and optical spectra covering the range 3700-10000 A with the 10.4m GTC telescope equipped with OSIRIS at La Palma (Spain), on Aug 19 and Aug 21. DG19ayfjc/AT2019nqz is located closer than 0.5 arcsec to the center of its host galaxy. On the stacked image with an exposure time of 3x10sec we could not detected the transient itself. From the emission lines of the host galaxy, a redshift z = 0.1076 +/- 0.0005 is measured, outside the expected LVC redshift range. The slit also covered the transient position, but no broad lines are detected. DG19aqbkc/AT2019nqc spectroscopy reveals narrow galaxy lines at redshift 0.078 +/- 0.001. Cross-correlating the transient spectrum (broad lines) with supernova template spectra in SNID (Blondin & Tonry, 2007), we find a good match to the spectra of SNIIP at about week after maximum at same redshift, about a week after maximum at the same redshift in agreement with the result reported by Buckley et al. (GCNC 25481). Therefore we consider both DG19qabkc/AT2019nqc and DG19ayfjc/AT2019nqz to be unrelated to the GW event S190814bv. [GCN OPS NOTE(31aug19): In the first sentence, "DG19aqbkc/AT2019nqc" was changed to "DG19qabkc/AT2019nqc". In the last sentence, "DG19aqbkc/AT2019nqc and DG19aqbkc/AT2019nqc" was changed to "DG19qabkc/AT2019nqc and DG19ayfjc/AT2019nqz". We thank C. Balcon (ISSP) for his comments. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25588 SUBJECT: LIGO/Virgo S190814bv: AT2019odc and AT2019omt 10.4m GTC spectroscopy DATE: 19/08/31 13:21:18 GMT FROM: Alberto J. Castro-Tirado at IAA-CSIC Y.-D. Hu and A. J. Castro-Tirado (IAA-CSIC), A. F. Valeev and V. V. Sokolov (SAO-RAS), E. Fernandez-Garcia (IAA-CSIC), I. Carrasco and A. Castellon (UMA), D. L. Tucker (Fermilab), M. Soares-Santos (Brandeis U), D. Garcia Alvarez (GRANTECAN, IAC, ULL) and M. Rivero (GRANTECAN), on behalf of a larger collaboration, report: Following the detection of desgw-190814r/AT2019odc and desgw-190814v/AT2019omt (Soarez-Santos et al. GCNC 25486) within the error area of the GW event S190814bv (LVC, GCNC 25324), we obtained imaging and optical spectra covering the range 5100-10000 A with the 10.4m GTC telescope equipped with OSIRIS in La Palma (Spain) starting on Aug 30, 04:00 UT. AT2019odc position lies in the bar of it host SBb galaxy, 0.7 arcsec away from its center. On the stacked image with an exposure time of 2x15 s we could not detect the transient itself. From the emission lines of the host galaxy, a redshift z = 0.0540 +/- 0.0005 is measured, inside the expected LVC redshift range. The slit also covered the transient expected position, but no broad lines were detected. AT2019omt is detected with r = 22.54 +/- 0.09 at Aug 30. Cross-correlating the spectrum (broad lines) with supernova template spectra in SNID (Blondin & Tonry, 2007), we find a good match to the spectra of SNIIL at several weeks post maximum at a redshift of 0.1564 +/- 0.0005, based on the narrow emission lines from the galaxy). Therefore we consider AT2019omt to be unrelated to the GW event S190814bv. This message can be quoted. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25596 SUBJECT: LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidate AT2019ntp DATE: 19/09/01 06:58:12 GMT FROM: Matthew Wiesner at Benedictine U LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidate AT2019ntp Matt Wiesner (Benedictine U), Melissa Butner (ETSU), Sahar Allam (Fermilab), Douglas Tucker (Fermilab), Mackenna Wood (UNC-Chapel Hill), Andrew Mann (UNC-Chapel Hill), Ósmar Rodríguez (UNAB), Nicolás Meza-Retamal (ESO Chile), Jonathan Quirola (PUC), Felipe Olivares (INCT/UDA), Regis Cartier (NOAO/CTIO), Sean Points (NOAO/CTIO), Marcelle Soares-Santos (Brandeis U), Clara Martinez-Vazquez (NOAO/CTIO), Alyssa Garcia (Brandeis U), Ken Herner (Fermilab), James Annis (Fermilab), Antonella Palmese (Fermilab), Nora Sherman (Fermilab and Brandeis U), Robert Morgan (U of Wisconsin-Madison), Tristan Bachmann (U Chicago), Tamara Davis (U Queensland) On behalf of the DESGW team*: We report SOAR Goodman spectroscopy of AT2019ntp, a possible counterpart to the black hole-neutron star merger S190814bv reported by the GROWTH team (GCN Circular No. 25393) based on data obtained by the DESGW team using the CTIO Blanco/DECam instrument. We obtained two exposures, one 45 min and one 30 min, using the Goodman instrument on the 4.1m SOAR telescope at Cerro Pachón. The analysis of these spectra allow us to conclude that 2019ntp is unrelated to the merger: 2019ntp appears to be consistent with a Type Ic-BL supernova (based on running the observed spectrum through the astrodash SN classification software package). The SOAR followup program is a partnership between the US (PIs: Kilpatrick & Tucker), Chilean (PI: Olivares), and Brazilian (PI: Makler) community. The candidates were identified in data taken by the DECam Search & Discovery Program for Optical Signatures of Gravitational Wave Events (DESGW, PI: Soares-Santos), which is carried out by the Dark Energy Survey (DES) collaboration in partnership with wide ranging groups in the community. DESGW uses data obtained with the Dark Energy Camera (DECam), which was constructed by the DES collaboration with support from the Department of Energy and member institutions, and utilizes data as distributed by the Science Data Archive at NOAO. NOAO is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes do Brasil (MCTIC/LNA), the U.S. National Science Foundation's National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). *The DESGW Collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner (ETSU), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25598 SUBJECT: LIGO/Virgo S190814bv: LCO Photometry of desgw-190814f/AT2019nte DATE: 19/09/01 20:57:09 GMT FROM: Shreya Anand at GROWTH Caltech Shreya Anand, Michael Coughlin, Igor Andreoni, and Tomas Ahumada report on behalf of Global Relay of Observatories Watching Transients Happen (GROWTH): We observed the nuclear transient desgw-190814f/AT2019nte, (Herner et al. GCN 25398) with the Siding Springs 2m Spectral imager of Las Cumbres Observatory (LCO) on 2019-08-22 and on 2019-08-27 in the g, r, and i-bands. To perform image subtraction, we used references from the DECam Legacy Survey (DECaLS) and the Dark Energy Survey (DES). The transient is not detected in g-band on either night to an upper limit of 20.3 mag. We show our photometry in g-, r-, and i-bands below: | UT dateobs | g mag | r mag | i mag | | 2019-08-22 | > 20.3 | 23.3 +/- 0.23 | > 21.0 | | 2019-08-27 | > 20.3 | 23.0 +/- 0.07 | 22.28 +/- 0.30 | Our measurements show a slow rise in the i-band for desgw-190814f, while the r-band measurements may be consistent with no evolution to within the uncertainties. We note that this transient host galaxy has a spectroscopic redshift from the 2dF survey (z~0.07) that is consistent with the LIGO/Virgo localization. We encourage further monitoring of this transient. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25599 SUBJECT: LIGO/Virgo S190814bv : No significant candidates in TAROT-GRANDMA observations DATE: 19/09/01 21:07:56 GMT FROM: Nelson Christensen at Obs.de la Cote dAzur,Nice D. Corre (LAL), M. Blazek (HETH/IAA-CSIC), A. Klotz (IRAP), N. Christensen (Artemis), M. Boer (Artemis), L. Eymar (Artemis), K. Noysena (Artemis, IRAP), S. Antier (APC), S. Basa (LAM), D. Coward (OzGrav-UWA), J.G. Ducoin (LAL), B. Gendre (OzGrav-UWA), P. Hello (LAL), D. A. Kann (HETH/IAA-CSIC), C. Lachaud (APC), N. Leroy (LAL), D. Turpin (NAOC), X. Wang (THU) report on behalf of the TAROT network and GRANDMA collaborations: We performed tiled observations of LIGO/Virgo event S190814bv (GCN #25324) with the TAROT-Reunion (Les Makes Observatory, La Reunion Island, France) telescope operating in clear filter. The observations started on 08/14/19 21:41:19 UTC which corresponds approximately to 31 minutes after the GW trigger time. We performed the following tiled observations : +------------+------------+---------+---------+---------+ | TStart | TEnd | RA | DEC | Proba | | [UTC] | [UTC] | [deg] | [deg] | [%] | |------------+------------+---------+---------+---------| | 2019-08-14 | 2019-08-14 | 9.3506 |-28.6364 | 0.4 | | 21:41:19 | 23:12:44 | | | | | 2019-08-14 | 2019-08-14 | 0.0000 |-32.7273 | < 0.1 | | 22:02:49 | 23:25:55 | | | | | 2019-08-14 | 2019-08-16 | 13.500 |-24.5454 | 76.0 | | 22:14:55 | 00:48:18 | | | | | 2019-08-14 | 2019-08-14 | 20.6897 | -8.1818 | < 0.1 | | 22:28:09 | 23:51:15 | | | | | 2019-08-14 | 2019-08-15 |354.8571 |-36.8182 | < 0.1 | | 22:47:06 | 00:09:59 | | | | | 2019-08-14 | 2019-08-14 | 4.6753 |-28.6364 | < 0.1 | | 23:00:04 | 23:04:30 | | | | | 2019-08-15 | 2019-08-15 | 9.0000 |-24.5454 | 6.3 | | 00:15:59 | 00:46:01 | | | | | 2019-08-15 | 2019-08-21 | 24.324 |-32.727 | 7.4 | | 19:54:58 | 01:01:29 | | | | +------------+------------+---------+---------+---------+ TStart and TEnd refer respectively to the time of the first and last exposure for a given tile. Observations are not necessarily continuous in this interval. The Probability refers to the 2D spatial probability of the GW skymap enclosed in a given tile. Each tile is 4.2x4.2 degrees. These observations cover about 89% of the cumulative probability of the LALInference skymap with HLV (posted at Aug 15, 2019 09:07:19 UTC) The typical limiting magnitude is 16.0 for a 60.0 s exposure due to bad conditions of observations. No serious transient candidates were found during our low latency analysis. The coverage map is available at: https://grandma-owncloud.lal.in2p3.fr/index.php/s/0aSCYiO1XqzHJkx Further analysis of the field (ra:13.500,dec:-24.5454) observed 64 min after the GW trigger time covering 76% of the LALInference skymap has been performed. No sources were found giving an upper limit at 16 mag for a possible optical counterpart. We have also found no source (3 sigma) at locations of desgw-190814j, desgw-190814m, desgw-190814o (GCN #25425), DG19hqpgc, DG19tzyhc, DG19wgmjc, DG19sevhc (GCN #25362), DG19vodmc, DG19gcwjc, DG19rzhoc, DG19tvtnc, DG19sbzkc, DG19hqhjc (GCN #25393), PS19epf, PS19eph (GCN #25356), desgw-190814a (GCN #25336), desgw-190814q (GN #25438). GRANDMA (Global Rapid Advanced Network Devoted to the Multi-messenger Addicts) is a network of robotic telescopes connected all over the world with both photometry and spectrometry capabilities for Time- domain Astronomy (https://grandma.lal.in2p3.fr/). Details on the TRE telescope are available on the GRANDMA web pages or on http://tarot.obs-hp.fr/. [GCN OPS NOTE(02sep19): Per author's request, MB's affiliation was corrected, and DAK was added to the author list.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25621 SUBJECT: LIGO/Virgo S190814bv: ATCA observation of ASKAP J005547-270433/AT2019osy DATE: 19/09/03 01:20:02 GMT FROM: Dougal Dobie at VAST Dougal Dobie (University of Sydney/CSIRO), Emil Lenc (CSIRO), Ian Brown (UWM), Tara Murphy (University of Sydney), Adam Stewart (University of Sydney), David Kaplan (UWM), Kunal Mooley (Caltech), Gregg Hallinan (Caltech) and the OzGrav, JAGWAR and GROWTH collaborations. We observed ASKAP J005547.4-270433/AT2019osy (GCN 25487) with the Australia Telescope Compact Array (ATCA) on 2019 August 29 from 14:00-22:00 UT. We report flux densities of: 369+/-23 uJy at 5.0 GHz 335+/-19 uJy at 6.0 GHz 307+/-15 uJy at 8.5 GHz 278+/-14 uJy at 9.5 GHz Fitting a power-law to these values we find a spectral index of alpha=-0.39+/-0.11, consistent with the value of -0.42 found by Mooley et al. (GCN 25539). Comparing to the VLA observations reported by Mooley et al. (GCN 25539), we find that the flux density has increased by ~40% in 1.5 days across 4.5-10 GHz. Additional epochs are required to separate intrinsic variability from contamination from propagation effects and systematics due to differing spatial resolution between the ATCA, VLA and ASKAP. Thank you to CSIRO staff for supporting these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25669 SUBJECT: LIGO/Virgo S190814bv: GRAWITA VST-ESO PARANAL observations and independent transient candidates discovery. DATE: 19/09/05 19:31:31 GMT FROM: Aniello Grado at INAF-OAC AUTHORS: A. Grado (INAF-Napoli), E. Cappellaro (INAF-Padova), E. Brocato (INAF-Abruzzo), S. Covino (INAF-Brera), F. Getman (INAF-Napoli), G. Greco (University Urbino) , P. D'avanzo (INAF-Brera), A. Rossi (INAF-OAS), E. Palazzi (INAF-OAS), S. Yang (INAF-Padova) on behalf of GRAWITA. We observed the field of S190814bv (GCN 25324 and updated GCN 25333) in r' band with the VLT Survey Telescope (VST) equipped with Omegacam (1 sqdeg FOV) (Proposal ID ESO 0103.D-0070 ). The field was observed for a total of 5 epochs distributed as reported in the following table. epoch 1 2019-08-15 from 08:50:26.860 to 10:13:47.602 epoch 2 2019-08-16 from 05:29:37.904 to 07:20:36.231 epoch 3 2019-08-19 from 04:55:59.697 to 06:08:28.809 epoch 3 2019-09-20 from 03:45:54.370 to 04:39:27.598 epoch 4 2019-8-22 from 03:01:00.585 to 05:41:44.089 epoch 5 2019-08-29 from 09:07:41.251 to 09:36:29.055 epoch 5 2019-08-30 from 07:49:42.449 to 09:34:10.334 all time are in UTC. In the first night we imaged 18 sqdeg covering 65% of the localization probability region. Starting from the second epoch we modified the pointings to improve the updated skymap coverage. The area imaged is 23 sqdeg covering 87% of the localization region. Each 1 sqdeg pointing was observed three times for a total exposure time of 135 seconds. Images were analized using the our photometric pipelines (Brocato et al. 2018 MNRAS, 474,1). The final vetting was done via visual inspection. The candidates were matched against the Minor Planet Center to further filter against slow moving asteroids. The three most outstanding candidates, already reported in TNS, and visible in at least three epochs are: Name | TNS Name | RA | Dec | Night | Mag | MAGERR VST J004656.70-252236.7 | AT2019npd | 00:46:56.711 | -25:22:36.43 | 2019-08-21 | 19.874 +/- 0.062 VST J004847.88-251823.5 | AT2019noq | 00:48:47.882 | -25:18:23.46 | 2019-08-15 | 19.962 +/- 0.033 VST J005605.55-243826.4 | AT2019nve | 00:56:05.510 | -24:38:26.40 | 2019-08-14 | 20.531 +/- 0.083 VST J004659.45-230559.5 | AT2019nyv | 00:46:59.451 | -23:05:59.50 | 2019-8-15 | 21.200 +/- 0.087 where the magnitude and night refers to the peak value. Automatic VST data processing was done with the VSTTube pipeline (Grado et al. 2012 Mem.SAIt 19, 362). The pointing sequence was generated using the GWsky script ( https://github.com/ggreco77/GWsky). We acknowledge excellent support from the ESO User Support Department and from ESO observing staff in Paranal. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25690 SUBJECT: LIGO/Virgo S190814bv: VLA/JAGWAR monitoring of the 50% containment region DATE: 19/09/09 23:54:35 GMT FROM: Kunal Mooley at NRAO,Caltech Kunal Mooley (NRAO, Caltech; Jansky Fellow), Steve Myers, Dale Frail (NRAO), Gregg Hallinan, Shri Kulkarni (Caltech), Alessandra Corsi, Arvind Balasubramanian, Deven Bhakta (TTU) report on behalf of the JAGWAR team We have initiated deep L band (1-2 GHz) multi-epoch observations of the 50% containment region (5 sq deg; GCN 25333) of the GW event S190814bv with the Karl G. Jansky Very Large Array. A total of 28 pointings (coordinates given below), observed as part of the JAGWAR program, will achieve a uniform RMS noise between 10-15 uJy over the 5 sq deg region. Additional pointings to cover cataloged high-mass and high-SFR galaxies are planned, and will be announced later. We will report any radio transients found through the GCN system. Observations of this region with other telescopes is encouraged. Ra, Dec of the VLA L band pointings: 00:49:05.24 -23:56:04.88 00:50:34.87 -23:56:04.88 00:52:04.50 -23:56:04.88 00:48:20.43 -24:18:28.88 00:49:50.06 -24:18:28.88 00:51:19.69 -24:18:28.88 00:52:49.32 -24:18:28.88 00:47:35.61 -24:40:52.88 00:49:05.24 -24:40:52.88 00:50:34.87 -24:40:52.88 00:52:04.50 -24:40:52.88 00:53:34.13 -24:40:52.88 00:46:50.80 -25:03:16.88 00:48:20.43 -25:03:16.88 00:49:50.06 -25:03:16.88 00:51:19.69 -25:03:16.88 00:52:49.32 -25:03:16.88 00:54:18.95 -25:03:16.88 00:47:35.61 -25:25:40.88 00:49:05.24 -25:25:40.88 00:50:34.87 -25:25:40.88 00:52:04.50 -25:25:40.88 00:53:34.13 -25:25:40.88 00:49:50.06 -25:48:04.88 00:51:19.69 -25:48:04.88 00:52:49.32 -25:48:04.88 00:54:18.95 -25:48:04.88 00:52:04.50 -26:10:28.88 We thank the NRAO staff/schedulers for executing these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25691 SUBJECT: LIGO/Virgo S190814bv: ATCA monitoring of ASKAP J005547-270433/AT2019osy DATE: 19/09/10 00:30:43 GMT FROM: Dougal Dobie at VAST Dougal Dobie (University of Sydney/CSIRO), Emil Lenc (CSIRO), Ian Brown (UWM),Tara Murphy (University of Sydney), Adam Stewart (University of Sydney), David Kaplan (UWM), Kunal Mooley (Caltech), Gregg Hallinan (Caltech) and the OzGrav, JAGWAR and GROWTH collaborations. We observed ASKAP J005547.4-270433/AT2019osy (GCN 25487) with the Australia Telescope Compact Array (ATCA) on 2019 September 6 from 12:30-19:30 UT. We report flux densities of: 380+/-21 uJy at 5.0 GHz 353+/-17 uJy at 6.0 GHz 299+/-14 uJy at 8.5 GHz 234+/-14 uJy at 9.5 GHz Which are consistent with the measurements obtained with the ATCA on 2019 August 29, 8 days prior (GCN 25487, GCN 25621, GCN 25539). Therefore the previously observed variability is unlikely to be related to S190814bv. Thank you to CSIRO staff for supporting these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25748 SUBJECT: LIGO/Virgo S190814bv: No counterpart candidate after completion of GRAWITA VST-ESO PARANAL transient survey. DATE: 19/09/14 09:00:44 GMT FROM: Sheng Yang at OAPD, INAF AUTHORS: S. Yang, E. Cappellaro (INAF-Padova), A. Grado (INAF-Napoli), E. Brocato (INAF-Abruzzo), S. Covino (INAF-Brera), F. Getman (INAF-Napoli), G. Greco (University Urbino), A. Rossi (INAF-OAS), E. Palazzi (INAF-OAS), A. Melandri, P. D'Avanzo (INAF-OAB), on behalf of GRAWITA. We have completed the transient search on the VST images obtained during the follow up observations of the GW trigger S190814bv. The survey coverage and observation epochs are reported in GCN 25324, 25333 and 25669. After calibration with the VSTtube pipeline, the images were processed via our image difference pipeline using as reference Panstarrs1/DeCam archive images. To select the candidates, we applied machine learning algorithms on subtracted images and then eyeballed the candidates with highest score. We removed from the list transients/variable detected only at one epoch and/or associated to stellar sources in the template images. We separate our detection in three groups: 1 - New transient candidates which we first reported in TNS. Name | TNS Name | RA (hms) | Dec (dms) | EPOCH | MJD | Mag (err) VST J0051091.73-2217406.9 | AT2019qbu | 00:51:09.173 | -22:17:40.69 | 2019-08-20T03:47:38.640 | 58715.16 | 21.191 +/- 0.092 VST J0044143.34-2507443.2 | AT2019qby | 00:44:14.334 | -25:07:44.32 | 2019-08-16T06:35:46.235 | 58711.27 | 21.354 +/- 0.022 VST J0056539.87-2759213.7 | AT2019qbz | 00:56:53.987 | -27:59:21.37 | 2019-08-16T07:10:09.945 | 58711.30 | 20.889 +/- 0.069 VST J0045485.40-2649390.1 | AT2019qca | 00:45:48.540 | -26:49:39.01 | 2019-08-30T07:51:26.759 | 58725.33 | 21.513 +/- 0.052 VST J0046190.62-2608431.9 | AT2019qcb | 00:46:19.062 | -26:08:43.19 | 2019-08-19T05:45:49.345 | 58714.24 | 21.554 +/- 0.043 VST J0053498.20-2445495.8 | AT2019qcc | 00:53:49.820 | -24:45:49.58 | 2019-08-30T08:23:58.534 | 58725.35 | 22.137 +/- 0.088 2 - Independent discoveries already reported in TNS by other groups (DES,PS1,ATLAS and ZTF). Name | TNS Name | RA (hms) | Dec (dms) | EPOCH | MJD | Mag (err) VST J0055423.01-2441499.3 | AT2019nvd | 00:55:42.301 | -24:41:49.93 | 2019-08-30T08:23:58.534 | 58725.35 | 21.099 +/- 0.047 VST J0050028.20-2241187.8 | AT2019mwp | 00:50:02.820 | -22:41:18.78 | 2019-08-16T06:18:19.852 | 58711.26 | 20.569 +/- 0.128 VST J0048043.98-2347509.4 | AT2019ntm | 00:48:04.398 | -23:47:50.94 | 2019-08-16T06:00:23.884 | 58711.25 | 21.072 +/- 0.108 VST J0100018.43-2642513.2 | AT2019ntr | 01:00:01.843 | -26:42:51.32 | 2019-08-16T07:01:13.473 | 58711.29 | 21.208 +/- 0.147 VST J0050120.72-2611525.6 | AT2019ntp | 00:50:12.072 | -26:11:52.56 | 2019-08-16T05:35:35.131 | 58711.23 | 21.043 +/- 0.027 VST J0048044.16-2347510.0 | AT2019ntm | 00:48:04.416 | -23:47:51.00 | 2019-08-16T06:00:23.884 | 58711.25 | 21.074 +/- 0.109 VST J0053055.60-2421387.1 | AT2019npz | 00:53:05.560 | -24:21:38.71 | 2019-08-19T06:06:44.348 | 58714.25 | 20.874 +/- 0.081 VST J0046168.14-2422211.9 | AT2019nxe | 00:46:16.814 | -24:22:21.19 | 2019-08-19T06:01:31.293 | 58714.25 | 20.868 +/- 0.067 VST J0100018.72-2642514.8 | AT2019ntr | 01:00:01.872 | -26:42:51.48 | 2019-08-16T07:01:13.473 | 58711.29 | 21.275 +/- 0.032 VST J0043204.93-2553020.7 | SN2019mbq | 00:43:20.493 | -25:53:02.07 | 2019-08-20T04:08:30.349 | 58715.17 | 18.830 +/- 0.037 VST J0049017.38-2314049.3 | AT2019nuj | 00:49:01.738 | -23:14:04.93 | 2019-08-20T03:47:38.640 | 58715.16 | 21.724 +/- 0.175 VST J0041333.30-2344319.5 | AT2019npe | 00:41:33.330 | -23:44:31.95 | 2019-08-22T03:41:56.360 | 58717.15 | 21.507 +/- 0.072 VST J0055523.99-2546598.1 | AT2019npw | 00:55:52.399 | -25:46:59.81 | 2019-08-16T05:40:03.236 | 58711.24 | 21.337 +/- 0.047 VST J0043301.60-2243293.5 | AT2019nsm | 00:43:30.160 | -22:43:29.35 | 2019-08-22T03:36:43.215 | 58717.15 | 21.388 +/- 0.093 VST J0055316.02-2258084.8 | AT2019num | 00:55:31.602 | -22:58:08.48 | 2019-08-22T03:23:49.543 | 58717.14 | 21.388 +/- 0.093 VST J0052433.39-2337536.4 | AT2019nva | 00:52:43.339 | -23:37:53.64 | 2019-08-22T03:13:23.501 | 58717.13 | 21.361 +/- 0.065 VST J0056466.93-2509332.9 | AT2019nqw | 00:56:46.693 | -25:09:33.29 | 2019-08-30T08:23:58.534 | 58725.35 | 20.772 +/- 0.030 3 - Candidates that are detected on our images but are below threshold of our search criteria. Name | TNS Name | RA (hms) | Dec (dms) | EPOCH | MJD | Mag (err) VST J0058064.56-2450142.8 | AT2019nzd | 00:58:06.456 | -24:50:14.28 | 2019-08-19T05:37:22.124 | 58714.23 | 21.175 +/- 0.095 VST J0057569.04-2434004.8 | AT2019nys | 00:57:56.904 | -24:34:00.48 | 2019-08-19T05:37:22.124 | 58714.23 | 21.305 +/- 0.099 VST J0053323.16-2349585.0 | SN2019npv | 00:53:32.316 | -23:49:58.50 | 2019-08-22T03:18:36.458 | 58717.14 | 21.618 +/- 0.087 In the tables above we reported the observing epochs and magnitudes (AB magnitude in r' band) at maximum for each candidates. All candidates show a slow evolution in the 2 weeks of the observed campaign (delta <1 mag), therefore we tentatively exclude that they are associated to the GW event. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25784 SUBJECT: LIGO/Virgo S190814bv: SOAR spectroscopy of AT2019nte host galaxy DATE: 19/09/19 18:44:06 GMT FROM: Douglas Tucker at Fermilab LIGO/Virgo S190814bv: SOAR spectroscopy of AT2019nte host galaxy Regis Cartier (NOAO/CTIO), César Briceño (NOAO/CTIO), Felipe Olivares (INCT/UDA), Douglas Tucker (Fermilab), Juanita Antilén (DAS/U de Chile), Ósmar Rodríguez (UNAB), Nicolás Meza-Retamal (ESO Chile), Jonathan Quirola (PUC), Sean Points (NOAO/CTIO), Sahar Allam (Fermilab), Melissa Butner (ETSU), Marcelle Soares-Santos (Brandeis U), Clara Martinez-Vazquez (NOAO/CTIO), Alyssa Garcia (Brandeis U), Ken Herner (Fermilab), James Annis (Fermilab), Antonella Palmese (Fermilab), Nora Sherman (Fermilab and Brandeis U), Robert Morgan (U of Wisconsin-Madison), Tristan Bachmann (U Chicago), Tamara Davis (U Queensland), On behalf of the DESGW team*: We report SOAR Goodman spectroscopy of the host galaxy of AT2019nte, possible counterpart to the black hole-neutron star merger S190814bv reported by the LVC in GCN Circulars No. 25324 and 25333. The candidate was found by the Blanco 4-m telescope by the DESGW team on CTIO Blanco DECam data (GCN Circular No. 25398). We obtained 2x900 sec exposures of the AT2019nte host galaxy (GALEXASC J013413.83-314318.3) using the Goodman instrument on the 4.1m SOAR telescope at Cerro Pachón. Analysis of these spectra allow us to infer a redshift of 0.0704 +/- 0.0004 from the Halpha and [NII] emission lines. This results is consistent with the redshift estimate reported in GCN Circular No. 25486. The SOAR followup program is a partnership between the US (PIs: Kilpatrick & Tucker), Chilean (PI: Olivares), and Brazilian (PI: Makler) community. The optical counterpart was identified by the DECam Search & Discovery Program for Optical Signatures of Gravitational Wave Events (DESGW, PI: Soares-Santos), which is carried out by the Dark Energy Survey (DES) collaboration in partnership with wide ranging groups in the community. DESGW uses data obtained with the Dark Energy Camera (DECam), which was constructed by the DES collaboration with support from the Department of Energy and member institutions, and utilizes data as distributed by the Science Data Archive at NOAO. NOAO is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes do Brasil (MCTIC/LNA), the U.S. National Science Foundation's National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). *The DESGW Collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner (ETSU), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soar es-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO). -- ======================================================================= Douglas L. Tucker Fermilab Tel: +1-630-840-2267 MS 127 FAX: +1-630-840-8274 PO Box 500 E-mail: dtucker@fnal.gov Batavia, IL 60510 USA http://home.fnal.gov/~dtucker/ ======================================================================= //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25801 SUBJECT: LIGO/Virgo S190814bv: HST and ALMA observations of the host galaxy of ASKAP J005547-270433 / AT 2019osy DATE: 19/09/21 18:03:22 GMT FROM: Daniele B Malesani at DTU Space F. E. Bauer (PUC), A. S. Fruchter (STScI), J. Gonzalez Lopez (UDP), J. Hjorth (DARK/NBI), T. Kangas (STScI), S. Kim (PUC), A. J. Levan (Radboud Univ.), D. B. Malesani (DTU Space), M. J. Michalowski (AMU), B. Milvang-Jensen (DAWN/NBI), R. Paladino (INAF/IRA), S. Schulze (WIS), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), report on behalf of the ENGRAVE collaboration: We observed the host galaxy of the radio transient ASKAP 005547-270433 / AT 2019osy (Stewart et al., GCN 25487) on 2019 Sep 17.9 UT using the F140W (1.4 micron) broadband filter of the Wide-Field Camera 3 on the Hubble Space Telescope and at 109 and 242 GHz in the configuration C43-7 (beam size of 0.21'' at 100 GHz) with ALMA on 2019 Sep 5.2 UT. A point source is detected by ALMA at 109 GHz consistent with the location reported by ASKAP (Stewart et al., GCN 25496), for which we measure these refined coordinates (~0.05" error): RA(J2000) = 00:55:47.417 Dec(J2000) = -27:04:33.14 We aligned the HST data to the Gaia catalog (to be consistent with the ALMA astrometry) using four stars in common inside the HST field of view. While we resolve a small elongated nucleus at the center of the host, we see no clear evidence of a point source superposed on the apparently normal structure of an edge-on spiral. Nonetheless, the position of the ALMA source aligns with the peak of the light in the nucleus to within its positional error of ~0.05". This result agrees with the finding of Mooley et al. (GCN 25539), who reported an alignment between the optical centroid of the host obtained from ground-based imaging and a VLA position at the 0.1" level. While the galaxy nucleus is not detected by ALMA at 242 GHz, a separate source is marginally detected approximately 1.5" away (not visible at 109 GHz), at a position still overlaying the stellar extent of the host galaxy and consistent with the ASKAP position of AT 2019osy (Stewart et al., GCNs 25487, 25496). The lack of detections by both ALMA at 109 GHz and by the VLA at 1-10 GHz (on Aug 28; Mooley et al., GCN 25539) makes it unlikely to be associated with AT 2019osy. It could be a noise peak, an unrelated background source, or a star-forming region inside the galaxy. Cutouts from the HST image, both wide-field and zoomed-in, can be seen at http://www.engrave-eso.org/AT2019osy_host_images . This circular is based on data collected under ALMA program 2018.1.01652.T, and on HST GO program #15664. We thank the staffs of STScI (in particular Alison Vick) and of the ALMA observatory for their assistance with these time-constrained observations. For further information on ENGRAVE, see http://www.engrave-eso.org/. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25822 SUBJECT: LIGO/Virgo S190814bv: Chandra X-ray non-detection of ASKAP J005547-270433 / AT2019osy DATE: 19/09/23 17:43:42 GMT FROM: Amruta Jaodand at Caltech Amruta Jaodand (Caltech), Sergio Campana (INAF/Brera), Murray Brightman (Caltech), Paolo D'Avanzo (INAF/Brera), Marianne Heida (Caltech), Fiona Harrison (Caltech), Giancarlo Ghirlanda (INAF/Brera), Mansi Kasliwal (Caltech), Kristin Madsen (Caltech), Kunal Mooley (Caltech), Maria Grazia Bernardini (INAF/Brera), Andrea Melandri (INAF/Brera), Om Sharan Salafia (INAF/Brera), Ruben Salvaterra (INAF/IASF Milano) We report on the Chandra X-ray follow-up of ASKAP J005547-270433 / AT2019osy, a candidate radio counterpart to GW190814bv (GCN 25324, 25621) identified by Stewart et. al (GCN 25487) located at RA + 00:55:47.40 (13.948deg), DEC: -27:04:33.00 (-27.076deg). We have observed the field of AT2019osy ~ days post merger starting at 2019-09-22T21:33:50 UT with the Chandra X-ray telescope. Earlier, optical follow-up reported a source with i=22.3 (Andreoni et al. GCN 25488), spatially coincident with the radio source, and Palomar 200-inch spectroscopic observations (Perley et al. GCN 25494) indicated that the flux could be arising from AGN variability. Follow-up VLA and ATCA radio observations (Mooley et al. GCN 25539; Dobie et al. 25691) showed that the radio flux did not continue increasing. Recent follow-up observations carried out with ALMA reported a detection at 109 GHz, consistent with the (RA 00:55:47.417, DEC -27:04:33.14) location reported by ASKAP, VLA and ATCA (Bauer et al. GCN 25801). An almost simultaneous HST observation provided evidence for a small elongated nucleus at the host center, but not for a point source (Bauer et al. GCN 25801). The Chandra observation failed to detect any X-ray source at the ASKAP J005547-270433 / AT2019osy position. No sources in the close vicinity are also apparent. A cross-match with the 2MASS archive shows a source should have been present at the location of the radio candidate. We derive a 95\% (0.3-8 keV) upper limit of 2.85e-4 counts/s. This converts to a 0.3-8 keV unabsorbed flux upper (nH=1.8e20 cm-2) limit of 3.2e-15 erg/cm2/s, assuming a power law spectrum with photon index 1.66 (motivated by radio observations, Dobie et al. GCN 25691), corresponding to a 0.3-8 keV unabsorbed luminosity of 4.2e40 erg/s. The lack of detection of any X-ray activity at such a low level, indicates that the emission of ASKAP J005547-270433 / AT 2019osy might not be due to the nucleus of the host galaxy. We thank Belinda Wilkes and the entire CXC staff for scheduling and enabling these observations at a rapid pace. [GCN OPS NOTE(24sep19): The extra header field was eliminated; the RA,DEC values were added into the first paragraph; and the signiture/contact block at the bottom of the CIrcualr was elimianted.] [GCN OPS NOTE(25sep19): Per author's request, the 25961 reference in the third paragraph was changed from 25961 to 25691.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25904 SUBJECT: LIGO/Virgo S190814bv: VLA 6 GHz observations of 75 galaxies in the 90% localization region DATE: 19/10/01 18:21:40 GMT FROM: Kate Alexander at Northwestern U K. D. Alexander, G. Schroeder, W. Fong, R. Margutti, (Northwestern), P. S. Cowperthwaite (Carnegie), E. Berger (Harvard), D. L. Coppejans (Northwestern), T. Laskar (University of Bath), A. MacFadyen (NYU), B. D. Metzger (Flatiron CCA, Columbia), G. Terreran (Northwestern), V. Ashley Villar (Harvard), and X. Xie (University of Southampton) report on behalf of a larger collaboration: We observed 75 galaxies within the 90% localization region of S190814bv (LIGO/Virgo et al., GCN 25324) with the Karl G. Jansky Very Large Array (VLA, program 19A-258, PI: Alexander). Observations were performed at a mean frequency of 6 GHz in a series of three observing blocks, with an average of 6.3 min of on-source time per galaxy. The observations were taken at mid-times of 34.4, 37.5, and 38.5 days after the merger. The galaxies were selected from the GLADE catalog (Dálya et al. 2018) using a priority ranking that combines each galaxy’s position within the 3D localization volume and its absolute magnitude in the B-band. Our observations covered 20% of the total integrated B-band luminosity within the localization volume. We created a 7 x 7 arcmin image centered on each galaxy, covering the VLA primary beam out to the half power radius. Pointing centers are listed below. Preliminary visual inspection yields detections of radio sources at or near the positions of 19 galaxies (representing 25% of our sample). The average 3-sigma limit at the center of our images is ~35 microJy. Further observations are planned to assess variability of any detected sources, and/or to detect any new sources on these timescales. We thank the VLA staff for their assistance in planning and executing these observations. Pointing Centers (RA, Dec J2000): 11.781363 -24.370647 12.180364 -23.561686 12.091079 -25.126814 11.870618 -25.440655 12.25617 -23.811317 13.173257 -25.733852 13.601437 -25.464052 12.874431 -24.642494 13.806392 -26.321253 12.828166 -26.16806 12.441799 -26.443037 12.793847 -25.954172 13.704722 -26.371256 11.543399 -24.650192 12.364808 -26.538301 11.771893 -24.238703 12.2428 -25.69345 12.178233 -23.773075 12.320091 -26.219179 13.788131 -25.455704 12.22897 -25.069471 12.473102 -24.707197 12.103154 -25.595707 12.311129 -23.858547 12.740481 -23.557995 13.490571 -24.543142 12.643789 -23.618547 11.472051 -23.772461 13.65696 -25.067099 12.42386 -25.050814 12.800914 -26.313063 11.867466 -23.02301 13.299205 -26.093979 12.726862 -23.631887 12.540436 -23.280048 13.804421 -24.044033 13.267828 -26.170792 13.064037 -24.69873 12.838246 -26.98945 12.346334 -26.507498 13.269273 -24.704401 12.551639 -25.975159 12.666141 -26.813395 12.385612 -26.538588 12.637869 -23.295488 11.9691 -25.8414 12.332034 -26.476397 13.477119 -24.077032 13.192388 -22.975018 13.358978 -26.599817 12.881038 -26.077213 11.7816 -25.66073 12.827568 -26.345284 11.264906 -25.019766 12.4675 -25.94625 13.3536 -25.8268 12.525684 -25.957939 12.808345 -26.461119 12.7184 -25.57706 11.054956 -24.327574 13.149672 -26.750933 11.555073 -25.950188 12.9027 -25.94219 13.566429 -23.535162 13.194542 -25.671635 12.6371 -25.95719 23.594837 -32.835316 11.3958 -24.24854 12.174922 -23.368631 13.570972 -23.552662 12.639195 -23.016602 13.522819 -23.194635 14.254662 -23.837297 12.8157 -25.9609 11.442945 -25.920193