//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24948 SUBJECT: LIGO/Virgo S190701ah: Upper limits from IceCube neutrino searches DATE: 19/07/01 21:12:46 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 S190701ah in a time range of 1000 seconds [3] centered on the alert event time (2019-07-01 20:24:46.578 UTC to 2019-07-01 20:41:26.578 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 S190701ah 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 S190701ah ranges from 0.029 to 0.176 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: 24950 SUBJECT: LIGO/Virgo S190701ah: Identification of a GW compact binary merger candidate DATE: 19/07/01 21:26:30 GMT FROM: Brandon Piotrzkowski at U of Wisconsin-Milwaukee The LIGO Scientific Collaboration and the Virgo Collaboration report: We identified the compact binary merger candidate S190701ah during real-time processing of data from LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) at 2019-07-01 20:33:06.578 UTC (GPS time: 1246048404.578). The candidate was found by the PyCBC Live [1], MBTAOnline [2], SPIIR [3], and GstLAL [4] analysis pipelines. S190701ah is an event of interest because its false alarm rate, as estimated by the online analysis, is 1.9e-08 Hz, or about one in 1 year, 7 months. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S190701ah The classification of the GW signal, in order of descending probability, is BBH (93%), Terrestrial (7%), 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%). Using the masses and spins inferred from the signal, there is strong evidence against matter outside the final compact object (HasRemnant: <1%). One sky map is available at this time and can be retrieved from the GraceDB event page: * bayestar.fits.gz, an updated localization generated by BAYESTAR [5], distributed via GCN notice about 4 minutes after the candidate For the bayestar.fits.gz sky map, the 90% credible region is well fit by an ellipse with an area of 67 deg2 described by the following DS9 region (right ascension, declination, semi-major axis, semi-minor axis, position angle of the semi-minor axis): icrs; ellipse(02h30m42s, -06d53m30s, 8d, 3d, 97d) Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1045 +/- 234 Mpc (a posteriori mean +/- standard deviation). There is substantial scattered light noise in L1 for several seconds around the trigger time. This may affect the accuracy of the skymap, but is not expected to affect the significance of the candidate. For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo Public Alerts User Guide . [1] Nitz et al. PRD 98, 024050 (2018) [2] Adams et al. CQG 33, 175012 (2016) [3] Qi Chu, PhD Thesis, The University of Western Australia (2017) [4] Messick et al. PRD 95, 042001 (2017)​ [5] Singer & Price PRD 93, 024013 (2016) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24951 SUBJECT: LIGO/Virgo S190701ah: No counterpart candidates in INTEGRAL SPI-ACS prompt observation DATE: 19/07/01 21:40:13 GMT FROM: Alexis Coleiro at APC/U. Paris Diderot A. Coleiro (APC, France), F. Onori (IAPS-Roma, Italy) V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland) J. Rodi (IAPS-Roma, Italy) S. Mereghetti (INAF IASF-Milano, Italy) 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 S190701ah (GCN 24950). At the time of the event (2019-07-01 20:33:06 UTC, hereafter T0), INTEGRAL was operating in nominal mode. The peak of the event localization probability was at an angle of 75 deg with respect to the spacecraft pointing axis. This orientation implies strongly suppressed (18% of optimal) response of ISGRI, strongly suppressed (36% of optimal) response of IBIS/Veto, and near-optimal (97% of optimal) response of SPI-ACS. The background within +/-300 seconds around the event was very stable (excess variance 1.1). 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 1.6e-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 ~1.4e-07 (5e-08) erg/cm^2/s at 1 s (8 s) time scale in 75-2000 keV energy range. For the mean reported distance 1045.0 Mpc this corresponds to the limit on the total isotropic equivalent energy in 1 s of 2.2e+49 erg for the short GRB spectrum and for a long GRB spectrum isotropic equivalent luminosity in 1 s (8 s) of 1.8e+49 erg/s (6.5e+48 erg/s) 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: 24952 SUBJECT: LIGO/Virgo S190701ah: No neutrino counterpart candidates in ANTARES search DATE: 19/07/01 21:43:12 GMT FROM: Antoine Kouchner at ANTARES Collaboration M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (APC/Université de Paris), M. Colomer (APC/Universite Paris Diderot)), D. Dornic (CPPM/CNRS), A. Kouchner (APC/Université 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 S190701ah event using the 90% contour of the bayestar probability map provided by the GW interferometers (GCN#24950 ). 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/S190701ah.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 2019-07-01 20:33:06 and in the 90% contour of the S190701ah event. The expected number of atmospheric background events in the region visible by ANTARES is 3.26e-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 2.35e-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: 24953 SUBJECT: LIGO/Virgo S190701ah: No counterpart candidates in AGILE-MCAL observations DATE: 19/07/01 21:49:27 GMT FROM: Fabrizio Lucarelli at SSDC/INAF-OAR F. Lucarelli, 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. Verrecchia (SSDC, and INAF/OAR), A. Bulgarelli, V. Fioretti, 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 S190701ah at T0 = 2019-07-01 20:33:06.578 (UT), an analysis of the AGILE minicalorimeter (MCAL) data shows that the S190701ah 90% c.l. localization region was entirely occulted by Earth at T0. Therefore, there are no AGILE-MCAL triggered events related to the GW event around the LIGO/Virgo T0. 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: 24956 SUBJECT: LIGO/Virgo S190701ah: Coverage and upper limits from MAXI/GSC observations DATE: 19/07/01 22:52:26 GMT FROM: Satoshi Sugita at Aoyama Gakuin U. S. Sugita, M. Serino (AGU), H. Negoro (Nihon U.), M. Sugizaki, N. Kawai (Tokyo Tech), M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi (Nihon U.), S. Nakahira, 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. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara, 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 (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 S190701ah at 2019-07-01 20:33:06.578 UTC (GCN 24950). At the trigger time of S190701ah, the high-voltage of MAXI/GSC was on, but the FOV was out of the 90% credible region of the bayestar skymap. The first one-orbit (92 min) scan observation with GSC after the event covered 90% of the 90% credible region of the bayestar skymap from 20:42:06 to 20:45:11 UTC (T0+540 to T0+725 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: 24959 SUBJECT: LIGO/Virgo S190701ah Global MASTER-Net observations report DATE: 19/07/02 00:37:13 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 S190701ah errorbox 12955 sec after trigger time at 2019-07-02 00:09:01 UT, with upper limit up to 17.2 mag. Observations started at twilight. The observations began at zenit distance = 54 deg. The sun altitude is -12.7 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=10448 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 12986 | 2019-07-02 00:09:01 | MASTER-Kislovodsk | ( 2h 25m 06.93s , - 6d 48m 44.68s) | C | 60 | 16.7 | 12986 | 2019-07-02 00:09:01 | MASTER-Kislovodsk | ( 2h 33m 13.66s , - 7d 17m 38.44s) | C | 60 | 16.3 | 13073 | 2019-07-02 00:10:29 | MASTER-Kislovodsk | ( 2h 25m 09.32s , - 4d 48m 49.39s) | C | 60 | 16.6 | 13073 | 2019-07-02 00:10:29 | MASTER-Kislovodsk | ( 2h 33m 14.14s , - 5d 17m 26.19s) | C | 60 | 16.1 | 13162 | 2019-07-02 00:11:58 | MASTER-Kislovodsk | ( 2h 25m 12.21s , - 2d 49m 12.05s) | C | 60 | 16.5 | 13162 | 2019-07-02 00:11:58 | MASTER-Kislovodsk | ( 2h 33m 16.00s , - 3d 17m 37.22s) | C | 60 | 16.4 | 13252 | 2019-07-02 00:13:27 | MASTER-Kislovodsk | ( 2h 25m 17.29s , + 1d 5m 19.06s) | C | 60 | 16.9 | 13252 | 2019-07-02 00:13:27 | MASTER-Kislovodsk | ( 2h 33m 21.37s , + 0d 37m 06.72s) | C | 60 | 16.5 | 13341 | 2019-07-02 00:14:56 | MASTER-Kislovodsk | ( 2h 25m 18.73s , + 3d 5m 37.48s) | C | 60 | 17.2 | 13341 | 2019-07-02 00:14:56 | MASTER-Kislovodsk | ( 2h 33m 24.07s , + 2d 37m 30.12s) | C | 60 | 16.6 | 13431 | 2019-07-02 00:16:27 | MASTER-Kislovodsk | ( 2h 33m 12.32s , - 9d 17m 18.56s) | C | 60 | 15.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24962 SUBJECT: LIGO/Virgo S190701ah: Upper limits from Fermi-GBM Observations DATE: 19/07/02 04:12:56 GMT FROM: Peter Veres at UAH P. Veres (UAH), R. Hamburg (UAH) and C. Fletcher (USRA) report on behalf of the Fermi-GBM Team and the GBM-LIGO/Virgo group: For S190701ah, and using the bayestar.fits skymap, Fermi-GBM was observing 100% of the localization probability at event time. There was no Fermi-GBM onboard trigger around the event time of the LIGO/Virgo detection of GW trigger S190701ah (GCN 24950). 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 spectral templates described in arXiv:1612.02395, we set the following 3 sigma flux upper limits over 10-1000 keV, weighted by GW localization probability (in units of erg/s/cm^2): Timescale soft norm hard -------------------------------------- 0.128 s: 5.1e-07 8.5e-07 1.2e-06 1.024 s: 1.5e-07 2.6e-07 3.9e-07 8.192 s: 3.5e-08 7.7e-08 1.5e-07 Assuming the median luminosity distance of 1045 Mpc (z=0.21) from the GW detection, we estimate intrinsic luminosity upper limits of (0.71-10)E49 erg/s for the soft template, (1.4-16)E49 erg/s for the normal template, and (4.6-36)E49 erg/s for the hard template over the 1 keV-10 MeV energy range. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24964 SUBJECT: LIGO/Virgo S190701ah: Upper limits from AGILE-GRID observations DATE: 19/07/02 09:48:44 GMT FROM: Fabrizio Lucarelli at SSDC/INAF-OAR F. Lucarelli, C. Pittori, F. Verrecchia (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), M. Cardillo, C. Casentini, G. Piano, A. Ursi (INAF/IAPS), A. Bulgarelli, V. Fioretti, 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 S190701ah at T0 = 2019-07-01 20:33:06.578 (UT), an analysis of the AGILE Gamma-Ray Imaging Detector (GRID) exposure at T0 showed that the S190701ah 90% c.l. localization region (LR) was entirely occulted by the Earth. However, full coverage of the S190701ah field was obtained around 1100 s after T0, at an off-axis angle of about 20 deg. We thus performed an analysis of the GRID data in the energy range 50 MeV - 10 GeV over a time interval of 100 s starting from T0+1100s. The following preliminary GRID 3-sigma upper limit (UL) values are obtained over the 100% of the exposed LR: (T0+1100s; T0+1200s): from 3.3e-08 to 3.7e-08 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: 24966 SUBJECT: LIGO/Virgo S190701ah: No counterpart candidates in the Swift/BAT Observations DATE: 19/07/02 12:59:23 GMT FROM: Takanori Sakamoto at AGU T. Sakamoto (AGU), S. D. Barthelmy (NASA/GSFC), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), 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 (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 S190701ah (LIGO/VIRGO Collaboration GCN Circ. 24950), where T0 is the LVC trigger time (2019-07-01T20:33:06.577 UTC). The center of the BAT FOV at T0 is RA = 10.445 deg, DEC = 41.252 deg, ROLL = 64.992 deg. The BAT Field of View (>10% partial coding) covers 87.22% of the integrated LVC localization probability, and 87.58% of the galaxy convolved probability (Evans et al. 2016). 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 ~ 8.11 x 10^-8 erg/s/cm^2. Event data are available from T0-100.77 to T0+99.42. No significant detections are found in the 15-350 keV images made using between T0-2.0 s and T0+8.0 s and whole event data duration. BAT retains decreased, but significant, sensitivity to rate increases for gamma-ray events outside of its FOV. About 12.78% 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/S190701ah/web/source.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24969 SUBJECT: LIGO/Virgo S190701ah: Upper limits from Insight-HXMT/HE observations DATE: 19/07/03 00:35:09 GMT FROM: QiBin Yi at IHEP, HXMT Q. B. Yi, S. Xiao, C. Cai, 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 S190701ah event (GCN #24950), trigger time 2019-07-01T20:33:06.578 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=40 deg, DEC=-15 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: 4.1e-08 erg cm^-2 10 s: 1.3e-07 erg cm^-2 Band model 2 (alpha=-1.0, beta=-2.3, Ep=230 keV): 1 s: 6.5e-08 erg cm^-2 10 s: 2.2e-07 erg cm^-2 Band model 3 (alpha=-0.0, beta=-1.5, Ep=1000 keV): 1 s: 1.7e-07 erg cm^-2 10 s: 7.2e-07 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: 24970 SUBJECT: LIGO/Virgo S190701ah: No transient candidates from CALET observations DATE: 19/07/03 03:00:41 GMT FROM: Yuta Kawakubo at Louisiana State U./CALET S. Ricciarini (U of Florence) A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The CALET Gamma-ray Burst Monitor (CGBM) was operating at the trigger time of S190701ah T0 = 2019-07-01 20:33:06.578 UT (The LIGO Scientific Collaboration and Virgo Collaboration, GCN Circ. 24950). No CGBM on-board trigger occurred around the event time. Based on the LIGO-Virgo localization sky map, the high probability area was outside of the CGBM field of view. The summed LIGO probabilities inside the CGBM HXM (7-3000 keV) and SGM (40 keV - 28 MeV) fields of view are 0% (and 30% credible region of the initial localization map was above the horizon). The HXM and SGM fields of view were centered at RA = 278.6 deg, Dec = 4.1 deg and RA = 286.9 deg, Dec = -1.6 deg at T0, respectively. Based on the analysis of the light curve data with 0.125 sec time resolution from T0-60 sec to T0+60 sec, we found no significant excess (signal-to-noise ratio >= 7) around the trigger time in either the HXM or the SGM data. The CALET Calorimeter (CAL) was operating in the low energy trigger mode at the trigger time of S190701ah, but the CAL FOV does not have any overlap with the LVC high probability localization region.  The CAL FOV was centered at RA= 286.8 deg, DEC= -1.6 deg at T0. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24971 SUBJECT: LIGO/Virgo S190701ah: KMTNet Observation DATE: 19/07/03 08:13:50 GMT FROM: Joonho Kim at Seoul National U. Myungshin Im (SNU), Joonho Kim (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 70% credible region (~34 deg^2) of the localization map of the BBH merger candidate, S190510g (LIGO/Virgo GCN 24950) with KMTNet at Chile (CTIO) starting at 2019-07-02 09:03:19 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 2deg pointing is given below. The search for transients is ongoing. target ra dec G331903-0 02:34:29.0 -05:50:16 G331903-1 02:26:10.6 -07:50:16 G331903-2 02:34:14.0 -07:50:16 G331903-3 02:26:27.3 -05:50:16 G331903-4 02:25:32.5 -09:50:16 G331903-5 02:33:38.3 -09:50:16 G331903-6 02:35:21.2 -03:50:16 G331903-7 02:27:20.6 -03:50:16 G331903-8 02:24:59.4 -11:50:16 G331903-9 02:36:13.6 -01:50:16 G331903-10 02:33:08.1 -11:50:16 G331903-11 02:28:13.6 -01:50:16 We thank the KMTNet observers for performing the observation. ᐧ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24987 SUBJECT: LIGO/Virgo S190701ah: Updated sky localization DATE: 19/07/05 17:26:16 GMT FROM: Brandon Piotrzkowski at U of Wisconsin-Milwaukee The LIGO Scientific Collaboration and the Virgo Collaboration report: We have conducted further analysis of the LIGO and Virgo data around the time of the compact binary coalescence (CBC) candidate S190701ah (GCN 24950). Parameter estimation has been performed using LALInference [1] and a new sky map, LALInference.offline.fits.gz, distributed via GCN Notice, is available for retrieval from the GraceDB event page: https://gracedb.ligo.org/superevents/S190701ah LALInference.offline.fits.gz is the preferred sky map at this time. The 90% credible region is 49 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1849 +/- 446 Mpc (a posteriori mean +/- standard deviation). Preliminary investigations indicate that the sky localization should not be biased on account of the scattered light in Livingston reported in GCN 24950; analyses including and excluding the affected low-frequency data give consistent results. 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) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25015 SUBJECT: LIGO/Virgo S190701ah: GRAWITA VST-ESO PARANAL observations DATE: 19/07/07 12:01:47 GMT FROM: Aniello Grado at INAF-OAC AUTHORS: A. Grado (INAF-Napoli), E. Cappellaro (INAF-Padova), S. Yang (INAF-Padova), F. Getman (INAF-Napoli), E. Brocato (INAF-Abruzzo), G. Greco (Universita' Urbino), S. Covino (INAF-Brera), L. Izzo (IAA) on behalf of GRAWITA. We observed 45 sqdeg covering the field of S170701ah (LIGO/Virgo, B. Piotrzkowski et al., GCN #24950, updated sky localization, B. Piotrzkowski et al., GCN #24987) in r' band with the VLT Survey Telescope (VST) equipped with Omegacam (1 sqdeg FOV) (Proposal ID ESO 0103.D-0070(A)). Observations started at 08:08 UT on 2019-07-04 and ended at 10:27 on 2019-07-04. They were performed under seeing conditions between 0.49” and 0.8”, at an airmass between 1.95 and 1.27. Each pointing covering 1 sqdeg was observed twice for a total exposure time of 80 seconds. The observations, that cover ~70% of the localization probability region, were organized in group of 3x3 deg, the coordinates of the center of each group are: RA(J2000) Dec(J2000) ------------------------ 02:27:14.69 -11:58:35.5 02:25:49.35 -08:58:35.5 02:24:49.23 -05:58:35.5 02:36:53.19 -05:58:35.5 02:36:14.47 -02:58:35.5 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: 25020 SUBJECT: LIGO/Virgo S190701ah: No counterpart candidates in Fermi-LAT observations DATE: 19/07/07 15:35:38 GMT FROM: Elisabetta Bissaldi at INFN,Bari M. Axelsson (KTH and Stockholm Univ.) and E. Bissaldi (Politecnico and INFN Bari) report on behalf of the Fermi-LAT Collaboration: "We have searched data collected by the Fermi Large Area Telescope (LAT) on July 1, 2019, for possible high-energy (E > 100 MeV) gamma-ray emission in spatial/temporal coincidence with the LIGO/Virgo trigger S190701ah (GCN 24950). 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 = 2019-07-01 20:33:06.578 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 3.4e-10 and 1.2e-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.