//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24098 SUBJECT: LIGO/Virgo S190412m: Identification of a GW binary merger candidate DATE: 19/04/12 07:28:32 GMT FROM: Peter Shawhan at U of Maryland/LSC The LIGO Scientific Collaboration and the Virgo Collaboration report: We identified the compact binary merger candidate S190412m during real-time processing of data from LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) at 2019-04-12 05:30:44.166 UTC (GPS time: 1239082262.166). The candidate was found by the GstLAL [1], SPIIR [2], CWB [3], MBTAOnline [4], and PyCBC Live [5] analysis pipelines. S190412m is a candidate of interest because its false alarm rate, as determined by the online analysis, is estimated to be 1.7e-27 Hz. The candidate's properties can be found at this URL: https://gracedb.ligo.org/superevents/S190412m The initial classification of the signal, in order of descending probability, is BBH (>99%), Terrestrial (<1%), BNS (<1%), NSBH (<1%), or MassGap (<1%). Assuming the candidate is astrophysical in origin, there is strong evidence against the lighter compact object having a mass < 3 solar masses (HasNS: <1%). The current estimate of the probability of nonzero remnant mass outside the final BH horizon (HasRemnant) reported in the GCN Notice is not reliable. One skymap is available at this time and can be retrieved from the GraceDB candidate page: * bayestar.fits.gz, a preliminary localization generated by BAYESTAR [6], distributed via GCN notice about an hour after the time of the candidate (delayed by a technical issue). For the bayestar.fits.gz skymap, the 90% credible region is 156 deg2. Marginalized over the whole sky, the luminosity distance estimate is 812 +/- 194 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] Qi Chu, PhD Thesis, University of Western Australia (2017) [3] Klimenko et al. PRD 93, 042004 (2016) [4] Adams et al. CQG 33, 175012 (2016) [5] Nitz et al. PRD 98, 024050 (2018) [6] Singer & Price PRD 93, 024013 (2016) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24099 SUBJECT: LIGO/Virgo S190412m: MASTER early alert observation DATE: 19/04/12 07:45:57 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, T.Pogrosheva, E. Gorbovskoy, N.Tyurina, V.Kornilov, D.Vlasenko, V.Vladimirov, D.Zimnukhov, A.Kuznetsov, P.Balanutsa, I.Gorbunov, A. Chasovnikov, V.Grinshpun, F.Balakin (Lomonosov Moscow State University, SAI, Physics Department), 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) R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O. Gress, N.M. Budnev, O.Ershova (Applied Physics Institute, Irkutsk State University), V. Yurkov, A. Gabovich, Yu. Sergienko, D. Kobcev (Blagoveschensk EducationState University), A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), MASTER Global Robotic Net (http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy,vol. 2010, 30L) automatically started LIGO/Virgo S190412m alert observations (Sjawhan et al. GCN 24098) MASTER-OAFA robotic telescope located in Argentina (OAFA observatory of San Juan National University) was pointed to the LIGO/Virgo S190412m alert 20 sec after notice time and 3839 sec after trigger time at 2019-04-12 06:34:43 UT. The 5-sigma upper limit has been about 18.16mag on the first image. Reduction and observation will be continued. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24100 SUBJECT: LIGO-Virgo S190412m: AGILE preliminary analysis DATE: 19/04/12 08:39:59 GMT FROM: Fabrizio Lucarelli at SSDC/INAF-OAR F. Lucarelli (SSDC, and INAF-OAR). G. Piano, A. Ursi (INAF/IAPS), Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), M. Cardillo, C. Casentini (INAF/IAPS), C. Pittori, F. Verrecchia (SSDC, and INAF/OAR), A. Bulgarelli, N. Parmiggiani (INAF/OAS-Bologna), M. Pilia (INAF/OA-Cagliari), F. Longo (Univ. Trieste and INFN Trieste), report on behalf of the AGILE Team: In response to the LIGO-Virgo GW event S190412m at T0 = 2019-04-12 05:30:44.17 (UT), a preliminary analysis of the AGILE exposure at T0 shows that the S190412m 90% c.l. localization region was occulted by the Earth. However, exposure of the field was obtained before and after T0. Additional analysis of AGILE data is in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24101 SUBJECT: INTEGRAL prompt observation of S190412m DATE: 19/04/12 09:35:53 GMT FROM: Volodymyr Savchenko at ISDC,U of Geneve Volodymyr Savchenko, Carlo Ferrigno (ISDC/UniGE, Switzerland) James Rodi, (IAPS-Roma, Italy) Sandro Mereghetti (INAF IASF-Milano, Italy) on behalf of the INTEGRAL multi-messenger collaboration: https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration Using INTEGRAL we have performed a search for a prompt gamma-ray counterpart of S190412m (GCN #24098). At the time of the event (2019-04-12 05:30:44 UTC, hereafter T0), INTEGRAL was operating in nominal mode. The peak of the event localization probability was at an angle of 120 deg with respect to the spacecraft pointing axis. This orientation implies a strongly suppressed response of IBIS, a somewhat suppressed response of IBIS/Veto, and a somewhat suppressed response of SPI-ACS. The SPI-ACS background within ±300 seconds around the event was very stable. We do not detect any significant counterparts and estimate a 3-sigma upper limit on the 75-2000 keV fluence of 2.9e-07 erg/cm^2for 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 ~2.5e-07 (9.1e-08) erg/cm^2/s at 1 s (8 s) time scale in 75-2000 keV energy range. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24102 SUBJECT: LIGO/Virgo S190412m: HAWC follow-up DATE: 19/04/12 10:25:13 GMT FROM: Israel Martinez-Castellanos at UMD/HAWC I. Martinez-Castellanos (University of Maryland) reports on behalf of the HAWC Collaboration: The HAWC Collaboration performed a follow-up of the gravitational wave triggerS190412m (GCN #24098). At the time of the trigger the HAWC local zenith was oriented towards (RA, Dec) = (185.3deg, 19.1deg). 99% of the GW candidate sky location probability fell within our observable field of view (0-45 deg zenith angle). We performed a search for a short timescale emission using 6 sliding time windows (dt = 0.3s, 1s, 3s, 10s, 30s and 100s), shifted forward in time by 20% of their width. We searched the 95% probability containment area in a timescale-dependent time period, from t0-5dt to t0+10dt, where t0 is the time of the GW trigger. No significant gamma-ray detection above the background was observed. The sensitivity of this analysis is greatly dependent on zenith angle, ranging from 4.5deg to 43.6deg for the area searched in this analysis. The 5sigma detection sensitivity to a 1s (100s) burst in the 80-800GeV energy ranges from 1.2e-06 erg/cm^2 to 7.8e-05 erg/cm^2 (6.7e-06 erg/cm^2 to 3.5e-04 erg/cm^2), depending on the zenith angle. HAWC is a TeV gamma ray water Cherenkov array located in the state of Puebla, Mexico. It is sensitive to the energy range ~0.1-100TeV, and monitors 2/3 of the sky every day with an instantaneous field-of-view of ~2 sr. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24103 SUBJECT: LIGO-Virgo S190412m: Search for neutrino counterparts with IceCube DATE: 19/04/12 11:35:09 GMT FROM: Erik Blaufuss at U. Maryland/IceCube The IceCube Collaboration (http://icecube.wisc.edu/) reports: IceCube has performed a search for track-like muon neutrino events consistent with the sky localization of S190412m in a time range of 1000 seconds centered on the alert event time (2019-04-12 05:22:24.166 UTC to 2019-04-12 05:39:04.166 UTC) during which IceCube was collecting good quality data. No track-like events are found in spatial coincidence with the 90% spatial containment of S190412A calculated from the map circulated in the initial notice. IceCube's sensitivity to point sources within the location spanned by the 90% spatial containment of S190412m ranges from 0.029 to 0.048 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 -- ------------------------------------------------------------------------------------ Erik Blaufuss email: blaufuss@umd.edu Department of Physics http://icecube.umd.edu/~blaufuss University of Maryland Phone: 301-405-6077 College Park, MD 20742 Office: PSC 2208E "Any chance collision, and I light up in the dark." ------------------------------------------------------------------------------------ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24104 SUBJECT: LIGO/Virgo S190412m: Hobby-Eberly Telescope VIRUS observations of target galaxies. DATE: 19/04/12 11:42:28 GMT FROM: J. Craig Wheeler at U.Texas Austin M. J. B. Rosell, Matthew Shetrone, J. Craig Wheeler, Karl Gebhardt, and Aaron Zimmerman, on behalf of the LIGO Hobby-Eberly Telescope Response (LIGHETR) team report the spectroscopic observation of the field of S190412m (GCN #24098) with the VIRUS IFU instrument on the HET. We sampled a prioritized list of 7 galaxies from the GLADE catalog that overlapped with the LIGO probability map and the observable pupil of the HET. The resulting data cube covers the wavelength 350 to 550 nm at a resolving power of 750. The effective limiting magnitude in the B band was 22 magnitudes. Each field is 50x50 arc seconds. We observed, in order, galaxies 213.485626+32.349361, 214.212296+31.609276, 214.199814+32.783714, 214.708557+32.501812, 214.905014+33.619785, 215.054092+33.497181 and 218.171326+34.651875 that were numbers 2, 3, 5, 4, 6, 1, and 13, respectively, on our a priori mass-weighted galaxy list. Report of the results will be submitted later. -- J. Craig Wheeler Samuel T. and Fern Yanagisawa Regents Professor of Astronomy University and University of Texas System Distinguished Teaching Professor President, American Astronomical Society, 2006-2008 Department of Astronomy 2515 Speedway, Stop C1400 Austin, TX 78712-1205 512-471-6407 http://www.as.utexas.edu/~wheel Supernova Explosions http://www.springer.com/us/book/9783662550526 Cosmic Catastrophes http://ebooks.cambridge.org/ebook.jsf?bid=CBO9780511536625 The Krone Experiment, Krone Ascending http://www.amazon.com/Krone-Ascending-ebook/dp/B00926QEGW //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24105 SUBJECT: LIGO/Virgo S190412m/G329483: ANTARES neutrino search DATE: 19/04/12 11:51:38 GMT FROM: Damien Dornic at CPPM,France M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (APC/Universite Paris Diderot), M. Colomer (APC/Universite Paris Diderot)), D. Dornic (CPPM/CNRS), A. Kouchner (APC/Universite Paris Diderot), 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 G329483/S190412m event using the 90% contour of the probability map provided by the GW interferometers at event time. The ANTARES visibility at the time of the alert, together with the 50% and 90% contours of the probability map are shown in https://www.cppm.in2p3.fr/~dornic/events_runo3/S190412m.png. Considering the location probability provided by the LIGO/Virgo collaborations, there is a 9.3% 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 and in the 90% contour of the G329483/S190412m event. The expected number of atmospheric background events in the region visible by ANTARES is 1.8e-5 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 2.3e-4 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: 24108 SUBJECT: LIGO/Virgo S190412m: Insight-HXMT/HE observation DATE: 19/04/12 15:11:33 GMT FROM: Qi Luo at IHEP Q. Luo, C. Cai, 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 GW trigger time (T0=2019-04-12 05:30:44 UTC). At T0, about 30% of the LIGO localization region was covered by the Insight-HXMT without occultation by the Earth. Within T0 ± 100 s, no significant excess events (SNR > 5 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 peak position of the LIGO-Virgo location probability map, 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): 1s: 5.6e-07 erg cm^-2 10s: 2.8e-06 erg cm^-2 Band model 2 (alpha=-1.0, beta=-2.3, Ep=230 keV): 1s: 7.8e-07 erg cm^-2 10s: 3.7e-06 erg cm^-2 Band model 3 (alpha=-0.0, beta=-1.5, Ep=1000 keV): 1s: 1.1e-06 erg cm^-2 10s: 4.6e-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 (record 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 telescope. Insight-HXMT is the first Chinese space X-ray telescope, which was fundedjointly 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: 24110 SUBJECT: LIGO-Virgo S190412m: AGILE GRID observations DATE: 19/04/12 15:41:29 GMT FROM: Fabrizio Lucarelli at SSDC/INAF-OAR F. Lucarelli (SSDC, and INAF-OAR), G. Piano (INAF/IAPS), F. Verrecchia, C. Pittori (SSDC, and INAF-OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), M. Cardillo, C. Casentini, A. Ursi (INAF/IAPS), A. Bulgarelli, N. Parmiggiani (INAF/OAS-Bologna), M. Pilia (INAF/OA-Cagliari), F. Longo (Univ. Trieste, and INFN Trieste) report on behalf of the AGILE Team: In response to the LIGO-Virgo GW event S190412m at T0 = 2019-04-12 05:30:44.17 (UT) (GCN #24098), a preliminary analysis of the AGILE exposure at T0 showed that the S190412m 90% c.l. localization region (LR) was occulted by the Earth (GCN #24100). We performed an analysis of the AGILE Gamma-Ray Imaging Detector (GRID) data in the energy range 30 MeV - 10 GeV, over two separate time intervals with good exposure of the S190412m 90% LR, before and after T0. The following preliminary GRID values of 3-sigma upper limits (UL) are obtained: (T0 - 700s; T0 - 600s): from 4.2e-08 to 2.1e-07 erg cm^-2 s^-1. LR coverage: <20%. (T0 + 1600s; T0 + 1800s): from 4.1e-08 to 2.3e-07 erg cm^-2 s^-1. LR coverage: ~70%. These measurements were obtained with AGILE observing a large portion of the sky in spinning mode. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24111 SUBJECT: LIGO/Virgo S190412m: MAXI/GSC Observations DATE: 19/04/12 16:43:33 GMT FROM: Satoshi Sugita at Aoyama Gakuin U. S. Sugita (AGU), H. Negoro (Nihon U.), M. Serino (AGU), M. Sugizaki, N. Kawai (Tokyo Tech), M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi (Nihon U.), S. Nakahira, T. Mihara, M. Matsuoka (RIKEN), T. Sakamoto, A. Yoshida (AGU), Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, T. Sato (Chuo U.), M. Shidatsu (Ehime U.), Y. Tachibana, K. Morita, M. Oeda, K. Shiraishi (Tokyo Tech), S. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara, N.Isobe, R. Shimomukai, M. Tominaga (JAXA), Y. Ueda, A. Tanimoto, T. Morita, S. Yamada, S. Ogawa (Kyoto U.), H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.), M. Yamauchi, S. Iwahori, Y. Kurihara (Miyazaki U.), T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU) report on behalf of the MAXI team: We examined the MAXI/GSC all-sky X-ray images (2-20 keV) obtained in the orbit after the LVC trigger S190412m at 2019-04-12 05:31:03 UTC (GCN 24098). At the trigger time of S190412m, the high-voltage of MAXI/GSC was off, and it was turned on at T0+175 sec. The one-orbit (92 min) scan of GSC covered 93.2% of the 90% error region of the bayestar skymap from 06:30:50 to 06:39:52 UTC (T0+3587 to 4129 sec). The scan was mainly performed by the degraded GSC_3 camera. No significant new source was found in the error region at the one-orbit scan. The 1-sigma averaged upper limit obtained from the scan was 66 mCrab at 2-20 keV. If you require information of X-ray flux by MAXI/GSC at specific coordinates, please contact the submitter of this circular by email. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24112 SUBJECT: LIGO/Virgo S190412m: Fermi-GBM Observations DATE: 19/04/12 18:52:52 GMT FROM: Adam Goldstein at Fermi-GBM, USRA A. Goldstein (USRA) reports on behalf of the Fermi-GBM Team and the GBM-LIGO/Virgo group For S190412m, and using the initial BAYESTAR skymap, Fermi-GBM was observing 99.8% of the localization probability region at event time. There was no Fermi-GBM onboard trigger around the event time of the LIGO/Virgo detection of a GW trigger (GCN 24098). 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 considering the 90% credible region of the GW localization. Using the representative soft, normal, and hard GRB-like spectral templates described in arXiv:1612.02395, we set the following 3 sigma flux upper limits over 10-1000 keV (in units of 10^-7 erg/s/cm^2): Timescale Soft Normal Hard ------------------------------------ 0.1 s: 4.7-5.7 9.1-10 25-27 1.0 s: 1.5-1.8 2.8-3.2 7.4-7.9 10 s: 0.5-0.6 0.9-1.0 2.3-2.4 Assuming the mean luminosity distance of 812 Mpc from the GW detection, we estimate intrinsic luminosity upper limits of (0.6-6.9)E49 erg/s for the soft template, (1.0-11)E49 erg/s for the normal template, and (4.2-50)E49 erg/s for the hard template over the 1 keV-10 MeV energy range. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24113 SUBJECT: LIGO/Virgo S190412m: J-GEM optical/NIR follow-up observations DATE: 19/04/12 19:10:32 GMT FROM: Masaomi Tanaka at Tohoku University Tanaka, M. (Tohoku U.), Niino, Y., Morokuma, T. (U. of Tokyo), Tominaga N. (Konan U.), Utsumi, Y. (Stanford U./SLAC), Yanagisawa, K. (NAOJ), Murata, K. L. (Tokyo Tech), Onozato, H. (Nishi-Harima Astronomical observatory), Akitaya, H. (Hiroshima U.), Itoh, R. (Bisei Astronomical observatory), Sekiguchi, Y. (Toho U.), Oasa, Y. (Saitama U.), on behalf of J-GEM collaboration We report our optical and near-infrared imaging observations for the gravitational wave event S190412m. We started our observations about 4.5 hours after receiving the alert. We performed 390 deg2 wide-field imaging survey, covering 88.5 % of probability region, using the Tomo-e Gozen camera on the 105-cm Kiso Schmidt telescope, a very wide-field (20 deg2 field-of-view) optical CMOS imager (Sako et al. 2018, SPIE, 10702, 107020J). A typical limiting magnitude is about 18.5 mag (no filter). Data reduction is in progress. We also performed galaxy-targeted observations for 63 galaxies (see the table below) selected from the GLADE catalog (Dalya et al. 2016) in the probability skymap of S190412m using the following telescopes/instruments. - 50 cm MITSuME telescope at Akeno Observatory and a 3 color imager (g, Rc, Ic) - 50 cm MITSuME telescope at Okayama Astrophysical Observatory and a 3 color imager (g, Rc, Ic) - 91 cm Okayama Astrophysical Observatory NIR Wide‐Field Camera (OAOWFC, J-band, Yanagisawa, K., et al. 2014, Proc. SPIE, 9147, 91476D, Yanagisawa, K., et al. 2016, Proc. SPIE, 9908, 99085D) - 200 cm Nayuta telescope at Nishi-Harima Astronomical Observatory and Nishiharima Infrared Camera (NIC) We found no apparent transient objects in these galaxies to the 5 sigma limiting magnitudes listed below. galid ra dec No fil G R I J obsid --------------- -------- ------- ------ ----- ----- ----- ----- -------------------- GL141846+305225 214.6935 30.8735 99.00 ---- ---- ---- 18.03 Kiso Schmidt,OAOWFC GL124935+150900 192.396 15.15 ---- 18.89 19.14 18.60 ---- MITSuME-Akeno GL144207+352623 220.531 35.4396 ---- ---- ---- ---- 19.40 Nayuta GL142013+332950 215.0541 33.4972 ---- 20.04 20.16 18.93 18.76 MITSuME-Akeno,OAOWFC GL121809-005110 184.5373 -0.8527 ---- ---- ---- ---- 17.91 Nayuta GL144212+335859 220.5516 33.983 ---- 19.36 20.14 ---- ---- MITSuME-Akeno GL141357+322058 213.4856 32.3494 ---- ---- 19.69 19.08 ---- MITSuME-Akeno GL145541+331353 223.9212 33.2313 ---- 20.11 20.25 19.61 ---- MITSuME-Akeno GL141937+333711 214.905 33.6198 ---- 20.04 20.16 19.41 18.76 MITSuME-Akeno,OAOWFC GL141348+323200 213.452 32.5335 ---- 20.02 20.29 19.53 ---- MITSuME-Akeno GL141648+324701 214.1998 32.7837 ---- 20.10 20.17 18.24 ---- MITSuME-Akeno GL145605+335817 224.0188 33.9714 ---- 20.39 20.12 19.00 ---- MITSuME-Akeno GL142010+320453 215.042 32.0813 99.00 ---- ---- ---- 18.46 Kiso Schmidt,OAOWFC GL141930+320951 214.8739 32.1641 ---- ---- ---- ---- 18.46 OAOWFC GL141400+322606 213.501 32.435 ---- 20.02 20.29 19.53 ---- MITSuME-Akeno GL144850+333747 222.2104 33.6296 18.57 ---- ---- ---- 18.39 Kiso Schmidt,Nayuta GL141935+315805 214.894 31.9682 ---- ---- ---- ---- 18.46 OAOWFC GL143933+342329 219.8879 34.3913 18.96 ---- ---- ---- ---- Kiso Schmidt GL144328+342849 220.8685 34.4804 18.75 ---- ---- ---- ---- Kiso Schmidt GL145608+330400 224.0347 33.0664 ---- 20.11 ---- ---- ---- MITSuME-Akeno GL145317+344500 223.3209 34.7498 ---- ---- ---- ---- 18.91 OAOWFC GL144338+341310 220.9077 34.2193 18.11 ---- ---- ---- ---- Kiso Schmidt GL145140+344338 222.9153 34.7271 ---- ---- ---- ---- 18.91 OAOWFC GL143724+341721 219.3511 34.2891 18.74 ---- ---- ---- ---- Kiso Schmidt GL145243+343036 223.1807 34.5101 ---- ---- ---- ---- 18.91 OAOWFC GL144726+333258 221.8566 33.5496 18.70 ---- ---- ---- ---- Kiso Schmidt GL145602+330229 224.008 33.0414 ---- 20.11 ---- ---- ---- MITSuME-Akeno GL141425+323945 213.6044 32.6625 ---- 20.02 20.29 19.53 ---- MITSuME-Akeno GL142016+333321 215.066 33.556 ---- 20.04 20.16 19.41 18.76 MITSuME-Akeno,OAOWFC GL143657+333905 219.2358 33.6513 18.99 ---- ---- ---- ---- Kiso Schmidt GL141445+312118 213.6871 31.3549 99.00 ---- ---- ---- ---- Kiso Schmidt GL141958+321041 214.9927 32.1781 ---- ---- ---- ---- 18.46 OAOWFC GL141042+314031 212.675 31.6753 99.00 ---- ---- ---- ---- Kiso Schmidt GL143722+343456 219.3409 34.5822 18.79 ---- ---- ---- ---- Kiso Schmidt GL145254+341026 223.2263 34.174 18.33 ---- ---- ---- ---- Kiso Schmidt GL145544+335031 223.9321 33.8419 ---- 20.39 20.12 19.00 ---- MITSuME-Akeno GL141930+320800 214.8758 32.1333 ---- ---- ---- ---- 18.46 OAOWFC GL141442+310132 213.673 31.0255 99.00 ---- ---- ---- ---- Kiso Schmidt GL141937+320803 214.9041 32.1342 ---- ---- ---- ---- 18.46 OAOWFC GL141317+321752 213.321 32.2979 ---- ---- 19.69 19.08 ---- MITSuME-Akeno GL144311+340241 220.7952 34.0448 ---- 19.36 20.14 ---- ---- MITSuME-Akeno GL144233+341714 220.6376 34.2873 19.04 ---- ---- ---- ---- Kiso Schmidt GL143710+333313 219.2925 33.5536 18.85 ---- ---- ---- ---- Kiso Schmidt GL145332+343927 223.382 34.6575 ---- ---- ---- ---- 18.91 OAOWFC GL145319+345357 223.3282 34.8992 17.91 ---- ---- ---- ---- Kiso Schmidt GL145554+330548 223.9732 33.0966 ---- 20.11 ---- ---- ---- MITSuME-Akeno GL145223+350140 223.0957 35.0277 18.62 ---- ---- ---- ---- Kiso Schmidt GL145242+350514 223.1733 35.0873 18.62 ---- ---- ---- ---- Kiso Schmidt GL143717+341608 219.3228 34.2688 18.74 ---- ---- ---- ---- Kiso Schmidt GL144156+340041 220.4842 34.0114 ---- 19.36 20.14 ---- ---- MITSuME-Akeno GL144854+333728 222.2247 33.6244 18.57 ---- ---- ---- 18.39 Kiso Schmidt,Nayuta GL141358+310446 213.4921 31.0794 99.00 ---- ---- ---- ---- Kiso Schmidt GL142314+325444 215.8095 32.9122 99.00 ---- ---- ---- ---- Kiso Schmidt GL145347+323627 223.4462 32.6076 18.19 ---- ---- ---- ---- Kiso Schmidt GL144456+333012 221.2344 33.5034 18.75 ---- ---- ---- ---- Kiso Schmidt GL141303+311435 213.2638 31.243 99.00 ---- ---- ---- ---- Kiso Schmidt GL145405+341331 223.5214 34.2252 18.08 ---- ---- ---- ---- Kiso Schmidt GL145516+333604 223.816 33.6011 18.35 ---- ---- ---- ---- Kiso Schmidt GL141318+311401 213.327 31.2335 99.00 ---- ---- ---- ---- Kiso Schmidt GL144932+332353 222.3853 33.3981 18.70 ---- ---- ---- ---- Kiso Schmidt GL144526+352547 221.3572 35.4297 99.00 ---- ---- ---- ---- Kiso Schmidt GL144243+334919 220.6794 33.8221 ---- 19.36 ---- ---- ---- MITSuME-Akeno GL141827+310941 214.611 31.1615 ---- ---- ---- ---- 18.03 OAOWFC Note that a limiting mag = 99.00 for Kiso Schmidt is due to failure in our real-time data analysis (typical depth is about 18.5 mag). These observations were done in the framework of J-GEM collaboration (Morokuma et al. 2016, PASJ, 68, L9). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24114 SUBJECT: LIGO/Virgo S190412m: Swift/BAT data search DATE: 19/04/13 02:23:29 GMT FROM: Amy Lien at GSFC A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (NASA/GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), A. A. Breeveld (MSSL-UCL), A. P. Beardmore (U. Leicester), 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. 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), B. Mingo (U. Leicester), 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. 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 S190412m (LIGO/VIRGO Collaboration GCN Circ. 24098), where T0 is the LVC trigger time (2019-04-12T05:30:44 UTC). The center of the BAT FOV at T0 is RA = 295.081 deg, DEC = -30.264 deg, ROLL = 84.881 deg. The BAT Field of View (>10% partial coding) covers 0.28% of the integrated LVC localization probability. 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, respectively. 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 ~ 7.25 x 10^-8 erg/s/cm^2. BAT retains decreased, but significant, sensitivity to rate increases for gamma-ray events outside of its FOV. About 99.71% 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 of those within the FOV. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24115 SUBJECT: LIGO/Virgo S190412m: Fermi-LAT search for a high-energy gamma-ray counterpart DATE: 19/04/13 09:48:33 GMT FROM: Elisabetta Bissaldi at INFN,Bari E. Bissaldi (INFN & Politecnico Bari), M. Axelsson (KTH & Stockholm Univ.) and N. Omodei (Stanford Univ.) report on behalf of the Fermi-LAT Collaboration: We have searched data collected by the Fermi Large Area Telescope (LAT) on April 12, 2019, for possible high-energy (E>100 MeV) gamma-ray emission in spatial/temporal coincidence with the LIGO/Virgo trigger S190412m. 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 ~99% of the LIGO probability at the time of the trigger (T0 = 2019-04-12 05:30:44 UTC), and reached 100% cumulative coverage after ~7 ks. We performed a search for a transient counterpart within the 90% contour of the LIGO map in a fixed time window from T0 to T0+10 ks. No significant new sources are found. We also performed a search which adapted the time interval of the analysis to the exposure of each region of the sky. Again, no significant candidate counterpart was found. Energy flux upper bounds for the fixed time interval between 100 MeV and 100 GeV for this search vary between 2e-10 and 3e-09 [erg/cm^2/s]. The Fermi-LAT point of contact for this event is Elisabetta Bissaldi (Elisabetta.Bissaldi@ba.infn.it). 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: 24116 SUBJECT: LIGO/Virgo S190412m: GOTO optical coverage - no notable counterparts DATE: 19/04/13 11:38:01 GMT FROM: Danny Steeghs at U.of Warwick/GOTO D.Steeghs(1), Lyman, J. (1), M.Dyer(3), D.Galloway(2), V.Dhillon(3), P.O'Brien(4), G.Ramsay(5), D.Pollacco(1), E.Thrane(2), S.Poshyachinda(6), E.Pallé(7), K.Ulaczyk(1), R.Cutter(1), A.Levan(1), T. Marsh(1), R.West(1), K.Wiersema(1), B.Gompertz(1), E.Stanway(1), K.Ackley(2), Y-L.Mong(2), A.Casey(2), M.Brown(2), E.Rol(2), J.Mullaney(3), S.Littlefair(3), L.Makrygianni(3), E.Daw(3), J.Maund(3), R.Starling(4), R.Eyles(4), U.Sawangwit(6), D.Mkrtichian(6), S.Awiphan(6), S.Aukkaravittayapun(6), P.Irawati(6), M.Kennedy(8), R.Breton(8) (1) Warwick University; (2) Monash University; (3) Univ. of Sheffield; (4) University of Leicester; (5) Armagh Observatory; (6) National Astronomical Research Institute of Thailand; (7) Instituto de Astrofisica de Canarias); (8) University of Manchester report on behalf of the GOTO collaboration: We report on optical observations with the Gravitational-wave Optical Transient Observer in response to S190412m (GCN #24098). Targeted observations across 18 pointings containing 94% of the source location probability (based on the initial BAYESTAR skymap) were performed between 20:28 UT and 22:48 UT Apr 12 2019. No new transients were detected that could be credibly associated with S190412m, in line with searches reported in Lipunov et al. (GCN #24099) and Weiland et al. (GCN #24107). Each pointing spans 4.9x3.7 square degrees and consisted of 3x60s exposures in ourL-band filter (400-700nm passband) with a typical 5-sigma photometric depth equivalent to g=19.4, based on a photometric calibration against PS1 sources. All pointings were observed twice. Images are processed immediately after acquisition using the GOTOphoto pipeline. Difference imaging was performed on the median of each triplet of exposures using recent survey observations of the same pointings. Source candidates were initially filtered using a classifier and cross-matched against a variety of catalogs, including the MPC and PS1. Human candidate vetting was performed during data acquisition and processing in case of notable detections. 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: 24126 SUBJECT: LIGO/Virgo S190412m: TAROT-GRANDMA observation report. DATE: 19/04/16 16:36:40 GMT FROM: Michel Boer at CNRS/ARTEMIS M. Boer, N. Christensen, L. Eymar (CNRS-UCA-OCA ARTEMIS), A. Klotz, K. Noysena (CNRS-UPS IRAP), S. Antier (CNRS-CEA-UP7 APC), S. Basa (CNRS-LAM), D. Corre (CNRS-UPSud LAL), M. Coughlin (Caltech), D. Coward (OzGrav-UWA),  J.-G. Ducoin (CNRS-UPSud LAL), B. Gendre (OzGrav-UWA), P. Hello (CNRS-UPSud LAL), C. Lachaud (CNRS-CEA-UP7 APC), N. Leroy (CNRS-UPSud LAL), D. Turpin (NAOC) report on behalf of the TAROT and GRANDMA collaborations. We performed tiled observations of LIGO-Virgo S190412m (GCNC #24098) event with the TCA (Calern Observatory, OCA, France) and TRE (Les Makes Observatory, La Réunion Island, France) telescopes in Clear filter. The observations started at 2019-04-12 15:39:00 UTC, about 10h after the GW trigger time. We performed the following tiled observations : For TRE +-------------------+---------------------+--------+-------+-------+ Tstart              | Tend                | RA     | DEC   | Proba | [UTC time]          | [UTC time]          | [deg]  | [deg] | [%] | +-------------------+---------------------+--------+-------+-------| 2019-04-12 18:39:12 | 2019-04-12 22:48:35 | 216.00 | 34.29 | 20.97 | 2019-04-12 18:48:00 | 2019-04-12 22:57:29 | 221.14 | 34.29 | 14.50 | 2019-04-12 19:51:03 | 2019-04-12 23:06:35 | 226.29 | 34.29 | 9.70 | 2019-04-12 18:03:00 | 2019-04-12 23:15:35 | 214.05 | 30.00 | 9.50 | 2019-04-12 16:44:21 | 2019-04-12 21:18:29 | 195.56 | 17.14 | 7.22 | 2019-04-12 15:39:01 | 2019-04-12 22:30:40 | 190.84 | 12.86 | 6.65 | 2019-04-12 15:52:37 | 2019-04-12 22:39:34 | 191.11 | 17.14 | 4.89 | +-------------------+---------------------+--------+-------+-------+ For TCA +-------------------+---------------------+--------+-------+-------+ Tstart              | Tend                | RA     | DEC   | Proba | [UTC time]          | [UTC time]          | [deg]  | [deg] | [%] | +-------------------+---------------------+--------+-------+-------| 2019-04-12 21:36:03 | 2019-04-13 02:57:34 | 214.70 | 33.64 | 7.23 | 2019-04-12 19:39:05 | 2019-04-13 03:06:35 | 213.02 | 31.82 | 6.49 | 2019-04-12 19:48:05 | 2019-04-13 02:12:36 | 215.48 | 31.82 | 6.24 | 2019-04-12 21:00:04 | 2019-04-13 03:24:35 | 216.87 | 33.64 | 4.96 | 2019-04-12 20:06:03 | 2019-04-13 03:33:35 | 223.34 | 33.64 | 4.83 | 2019-04-12 21:18:05 | 2019-04-12 03:42:35 | 219.04 | 33.64 | 4.43 | 2019-04-12 21:27:04 | 2019-04-12 03:51:35 | 217.78 | 33.46 | 3.74 | +-------------------+---------------------+--------+-------+-------+ The Probability refers to the 2D spatial probability of the GW skymap enclosed in a given tile. The size of the tiles are 4.2x4.2 deg2 for TRE and 1.8 x 1.8 deg2 for TCA. These observations cover 73% and 38% of the 90% GW probability skymap for TRE and TCA respectively. The typical 3 sigma limiting magnitude for a 2 minute exposure is 17 for TRE and 18 for TCA. Results of the on-going analysis  will be reported in a later GCNC. 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 TAROT telescopes are available on the GRANDMA web pages or on http://tarot.obs-hp.fr/ This circular is citable. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24136 SUBJECT: LIGO/Virgo S190412m: SVOM/GWAC observations of the initial skymap DATE: 19/04/20 00:46:03 GMT FROM: Chao Wu at NAOC X.H. Han (NAOC), J.Y. Wei (NAOC), C. Wu (NAOC), L.P. Xin (NAOC), D. Turpin (NAOC), N. LEROY (CNRS/LAL), S. ANTIER (CNRS/APC/CNES), L. Huang (NAOC), Y. Xu (NAOC), H.B. Cai (NAOC), J. Wang (NAOC), X.M. Lu (NAOC), Y.L. Qiu (NAOC), J.S. Deng (NAOC), L. Jia (NAOC), S.C. Zou (NAOC), S.F. Liu (NAOC), Q.C. Feng (NAOC), H.L. Li (NAOC), D.W. Xu (NAOC), Y.J. Xiao (NAOC), W.L. Dong (NAOC), Y.T. Zheng (NAOC), P. P. Zhang (NAOC), R.S. Zhang (NAOC), E.W. Liang (GXU), X.G. Wang (GXU), Z.G. Dai (NJU), X.Y. Wang (NJU), Y.G. Yang (HBNU), J.R. Mao (YNAO), B. Cordier (CEA/AIM), S. Basa (CNRS/LAM), J.L. Atteia (UPS/IRAP), D. Gotz (CEA/AIM), A. Claret (CEA/AIM), C. Lachaud (CNRS/APC), R. Duque (CNRS/IAP), N. Dagoneau (CEA/AIM) S.N. Zhang (IHEP), B.B. Wu (IHEP), report on behalf of the SVOM Ground Follow-up Group: We observed 7 sky regions (total: 1100 square degrees) to cover the skymap of the advanced LIGO/Virgo trigger S190412M, with SVOM/GWAC, at Xinglong Observatory equipped with a set of two types of wide angle cameras: FFOV cameras (FOV~900 square degrees/camera, aperture = 3.5 cm) and JFOV cameras (FOV~150 square degrees/camera, aperture = 18 cm). SVOM/GWAC currently comprises 4 FFOV cameras and 16 JFOV cameras, working with unfiltered band. The observations are operated in time-series mode, taking one exposure every 15 seconds (10s exposure + 5s readout). We estimate a 95% prior probability that these 7 regions contain the true location of the source. The coordinates of the 7 regions and observation time are list following: No. Ra Dec start-obs(UTC) end-obs(UTC) Telescope_ID 1 12:16:08.501 +13:42:34.43 2019-04-12 14:21:03 2019-04-12 14:53:31 2 2 13:04:12.375 +13:07:23.42 2019-04-12 14:21:03 2019-04-12 14:53:31 2 3 13:01:14.699 +01:23:57.03 2019-04-12 14:21:03 2019-04-12 14:53:31 2 4 14:15:50.897 +35:59:33.54 2019-04-12 14:05:51 2019-04-12 14:20:11 2 5 15:42:30.509 +35:59:41.27 2019-04-12 14:05:51 2019-04-12 14:20:11 2 6 12:16:49.785 +01:39:44.92 2019-04-12 14:21:03 2019-04-12 14:53:31 2 7 14:47:20.959 +36:20:07.37 2019-04-12 14:05:51 2019-04-12 14:20:11 2 The covering map is available at: http://cmm.svom.cn/gwpub/O3/S190412m/S190412m_GWAC.png (user:svomo3 pwd:gwo3) The first image was taken ~8 hours after the event trigger time. The weather conditions were bad (cloudy) during the observations. A 3 sigma limiting magnitude of about 14 mag in R band is obtained in our single frames. No credible new source is detected by our online pipeline. A more detailed image analysis including co-addition is ongoing with our offline pipeline to search for transient candidates. This circular is citable.