//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26926 SUBJECT: LIGO/Virgo S200129m: Identification of a GW compact binary merger candidate DATE: 20/01/29 08:05:31 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 S200129m during real-time processing of data from LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) at 2020-01-29 06:54:58.435 UTC (GPS time: 1264316116.435). The candidate was found by the GstLAL [1], CWB [2], PyCBC Live [3], MBTAOnline [4], and SPIIR [5] analysis pipelines. Some scattering noise could be seen around the time of the event in Virgo data; follow-up studies are on-going. We will update the localization if warranted by offline analysis. S200129m is an event of interest because its false alarm rate, as estimated by the online analysis, is 6.7e-32 Hz, or about one in 1e23 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S200129m The classification of the GW signal, in order of descending probability, is BBH (>99%), Terrestrial (<1%), BNS (<1%), MassGap (<1%), or NSBH (<1%). Assuming the candidate is astrophysical in origin, the probability that the lighter compact object has a mass < 3 solar masses (HasNS) is <1%. Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. Two sky maps are available at this time and can be retrieved from the GraceDB event page: * bayestar.fits.gz,0, an initial localization generated by BAYESTAR [6], distributed via GCN notice about 4 minutes after the candidate event time. * bayestar.fits.gz,1, an initial localization generated by BAYESTAR [6], distributed via GCN notice about 13 minutes after the candidate event time. The preferred sky map at this time is bayestar.fits.gz,1. For the bayestar.fits.gz,1 sky map, the 90% credible region is 53 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 908 +/- 202 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] Klimenko et al. PRD 93, 042004 (2016) [3] Nitz et al. PRD 98, 024050 (2018) [4] Adams et al. CQG 33, 175012 (2016) [5] Qi Chu, PhD Thesis, The University of Western Australia (2017) [6] Singer & Price PRD 93, 024013 (2016) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26927 SUBJECT: LIGO/Virgo S200129m: Upper limits from IceCube neutrino searches DATE: 20/01/29 08:08:31 GMT FROM: Alex Pizzuto at ICECUBE/U of Wisconsin 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 S200129m in a time range of 1000 seconds [3] centered on the alert event time (2020-01-29 06:46:38.435 UTC to 2020-01-29 07:03:18.435 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 S200129m calculated from the map circulated in the 3-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 S200129m ranges from 0.029 to 0.044 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] PoS(ICRC2019)918 and Braun et al., Astroparticle Physics 29, 299 (2008) [3] Baret et al., Astroparticle Physics 35, 1 (2011) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26928 SUBJECT: LIGO/Virgo S200129m: No counterpart candidates in INTEGRAL SPI-ACS prompt observation DATE: 20/01/29 08:15:41 GMT FROM: Francesca Onori at INAF/IAPS LIGO/Virgo S200129m: No counterpart candidates in INTEGRAL SPI-ACS prompt observationFrancesca Onori (IAPS, Italy), Sergey Molkov (IKI, Moscow) V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland) J. Rodi (IAPS-Roma, Italy) A. Coleiro (APC, France) S. Mereghetti (INAF IASF-Milano, Italy)on behalf of the INTEGRAL multi-messenger collaboration: https://www.astro.unige.ch/cdci/integral-multimessenger-collaborationUsing INTEGRAL/SPI-ACS realtime data (following [1]) we have performed a search for a prompt gamma-ray counterpart of S200129m (GCN 26926).At the time of the event (2020-01-29 06:54:58 UTC, hereafter T0), INTEGRAL was operating in nominal mode. The peak of the event localization probability was at an angle of 112 deg with respect to the spacecraft pointing axis. This orientation implies strongly suppressed (5% of optimal) response of ISGRI, somewhat suppressed (44% of optimal) response of IBIS/Veto, and strongly suppressed (37% 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 4.5e-07 erg/cm^2 (within the 50% probability containment region of the source localization) for a burst lasting less than 1s 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 300s 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 ~4.1e-07 (1.3e-07) erg/cm^2/s at 1s (8s) time scale in 75-2000 keV energy range.For the mean reported distance 908.0 Mpc this corresponds to the limit on the total isotropic equivalent energy in 1s of 4.5e+49 erg for the short GRB spectrum and for a long GRB spectrum isotropic equivalent luminosity in 1s (8s) of 3.7e+49 erg/s (1.3e+49 erg/s)We report for completeness and in order of FAP, all excesses identified in the search region. We find: 1 possibly associated excess:T-T0 | scale | S/N | luminosity ( x 1e+49 erg/s) | FAP -1.52 | 0.1 | 4.2 | 20.7 +/- 4.89 +/- 6.38 | 0.03944 likely background excesses:T-T0 | scale | S/N | luminosity ( x 1e+49 erg/s) | FAP -16.2 | 1.95 | 3.4 | 3.88 +/- 1.09 +/- 1.2 | 0.0685 -38.6 | 0.5 | 3.8 | 8.01 +/- 2.16 +/- 2.48 | 0.344 25.7 | 0.15 | 4.4 | 17.8 +/- 3.98 +/- 5.51 | 0.373 -121 | 0.4 | 4.2 | 10.3 +/- 2.42 +/- 3.18 | 0.775Note that FAP estimates (especially at timescales above 2s) may be possibly further affected by enhanced non-stationary local background 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 -- Dr. Francesca Onori Postdoctoral Researcher IAPS, via Fosso del Cavaliere, 100, 00133 - Rome, Italy e-mail: francesca.onori@inaf.it Tel: +39 06 45488128 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26929 SUBJECT: LIGO/Virgo S200129m: Coverage and upper limits from MAXI/GSC observations DATE: 20/01/29 09:14:50 GMT FROM: Hitoshi Negoro at Nihon U M. Serino, S. Sugita (AGU), N. Kawai (Tokyo Tech), H. Negoro (Nihon U.), M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi, R. Takagi (Nihon U.), T. Mihara, C. Guo, Y. Zhou, 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, 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), M. Sugizaki (NAOC) report on behalf of the MAXI team: We examined MAXI/GSC all-sky X-ray images (2-20 keV) after the LVC trigger S200129m at 2020-01-29 06:54:58.435 UTC (GCN 26926). At the trigger time of S200129m, the high-voltage of MAXI/GSC was off, and it was turned on at T0+195 sec (+3.3 min). The first one-orbit (92 min) scan observation with GSC after the event covered 100% of the 90% credible region of the bayestar skymap from 07:06:13 to 07:11:43 UTC (T0+675 to T0+1005 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: 26930 SUBJECT: LIGO/Virgo S200129m: upper limits from AGILE/MCAL observations DATE: 20/01/29 09:22:28 GMT FROM: Carlotta Pittori at ASI SSDC, INAF-OAR 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), F. Lucarelli (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 S200129m at T0 = 2020-01-29 06:54:58.435 (UT), 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 S200129m 90% c.l. localization region was accessible to the AGILE MCAL. 3-sigma upper limits (ULs) are obtained for a 1 s integration time at different celestial positions within the accessible S200129m localization region, from a minimum of 1.3E-06 erg cm^-2 to a maximum of 2.7E-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: 26931 SUBJECT: LIGO/Virgo S200129m: upper limits from AGILE/GRID observations DATE: 20/01/29 09:38:59 GMT FROM: Carlotta Pittori at ASI SSDC, INAF-OAR 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), F. Lucarelli (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 S200129m at T0 = 2020-01-29 06:54:58.435 (UT) a preliminary analysis of the AGILE exposure at T0 shows that the Gamma-Ray Imaging Detector (GRID) exposure covered less than 10% of the 90% c.l. localization region (LR) (due to solar panel constraints). We performed an analysis of the GRID data in the energy range 50 MeV - 10 GeV over time intervals before and after T0, where good exposure of the S200129m 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: from 8.3e-07 to 9.1e-06 erg cm^-2 s^-1, with exposure of about 51% of the LR over the time interval ( T0 + 100s ; T0 + 200s ); 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: 26933 SUBJECT: LIGO/Virgo S200129m: Global MASTER-Net observations report DATE: 20/01/29 11:32:16 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, D. Cheryasov (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-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the LIGO/Virgo S200129m errorbox 15067 sec after trigger time at 2020-01-29 11:06:05 UT, with upper limit up to 16.4 mag. Observations started at twilight. The observations began at zenith distance = 74 deg. The sun altitude is -11.8 deg. The galactic latitude b = -29 deg., longitude l = 56 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/ligo_1.php?id=11295 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 15157 | 2020-01-29 11:06:05 | MASTER-Tunka | (21h 12m 26.71s , +12d 10m 03.5s) | C | 180 | 14.1 | 15402 | 2020-01-29 11:10:09 | MASTER-Tunka | (21h 12m 30.70s , +12d 11m 17.9s) | C | 180 | 15.2 | 15903 | 2020-01-29 11:18:31 | MASTER-Tunka | (21h 14m 27.13s , +14d 09m 07.8s) | C | 180 | 16.4 | 16115 | 2020-01-29 11:22:03 | MASTER-Tunka | (20h 38m 50.12s , +22d 10m 14.8s) | C | 180 | 15.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26936 SUBJECT: LIGO/Virgo S200129m: Not observable by Fermi-GBM DATE: 20/01/29 17:07:21 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 S200129m and using the bayestar.fits.gz,1 skymap, Fermi-GBM did not observe any of the localization probability at event time due to Earth occultation. Therefore, the GBM observations are not constraining for prompt gamma-ray emission. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26937 SUBJECT: LIGO/Virgo S200129m: No counterpart candidates in Fermi-LAT observations DATE: 20/01/29 19:59:30 GMT FROM: Milos Kovacevic at INFN Perugia M. Axelsson (KTH & Stockholm Univ.), F. Longo (University and INFN, Trieste), M. Kovacevic (INFN Perugia), E. Bissaldi (Politecnico & INFN Bari), D. Kocevski (NASA/MSFC), N. Omodei (Stanford Univ.) and M. Arimoto (Kanazawa University) report on behalf of the Fermi-LAT Collaboration: We have searched data collected by the Fermi Large Area Telescope (LAT) on January 29, 2020, for possible high-energy (E > 100 MeV) gamma-ray emission in spatial/temporal coincidence with the LIGO/Virgo trigger S200129m (GCN 26926). 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 time, and "cumulative coverage" as the integral of the instantaneous coverage over time. At the time of the trigger (T0 = 2020-01-29 06:54:58.435 UTC), no part of the LIGO probability map was observable by Fermi-LAT. The region entered the LAT field of view around T0 + 3 ks, and 100% cumulative coverage was reached after ~8.8 ks. We performed a search for a transient counterpart within the observed region of the 90% contour of LIGO map in a fixed time window from T0 + 3 ks to T0 + 10 ks. No significant new 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 2.9e-10 and 7.1e-10 [erg/cm^2/s]. The Fermi-LAT point of contact for this event is Makoto Arimoto (arimoto@se.kanazawa-u.ac.jp) 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: 26938 SUBJECT: LIGO/Virgo S200129m: NED Galaxies in the 50% Localization Volume DATE: 20/01/29 20:02:14 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 S200129m trigger sky localization with the galaxies in NED and found 909 galaxies within the 90% containment. Due to the large number of candidates in this volume, we provide here the top 20 (out of 252) galaxies located in the 50% volume sorted by 2MASS absolute K-band magnitude. 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. objname ra dec DistMpc k_m_k20fe M_Ks dP_dV ---------------------------- -------- -------- ------- --------- ---------- -------- 2MASX J21112414+0730549 317.8505 7.5152 885.09 13.093 -26.641947 3.91e-07 2MASX J21153810+0154415 318.9088 1.9116 948.02 13.333 -26.551079 3.40e-07 2MASX J21075194+0554019 316.9664 5.9004 757.87 12.925 -26.472973 1.69e-07 2MASX J21185415+0124556 319.7257 1.4155 976.72 13.498 -26.45084 2.08e-07 2MASX J21103552+0750027 317.6480 7.8342 833.18 13.163 -26.440691 3.93e-07 2MASX J21155885+0200085 318.9952 2.0024 938.12 13.421 -26.440298 3.70e-07 2MASX J21143195+0414596 318.6333 4.2500 919.87 13.418 -26.400635 6.34e-07 2MASX J21094540+0607107 317.4393 6.1197 714.28 12.901 -26.368343 3.20e-07 2MASX J21162901+0410260 319.1210 4.1739 949.09 13.546 -26.34054 3.98e-07 2MASX J21164905+0117390 319.2043 1.2943 996.72 13.672 -26.320866 2.38e-07 2MASX J21145876+0432013 318.7448 4.5338 872.70 13.384 -26.320324 5.53e-07 2MASX J21135815+0637355 318.4923 6.6264 832.72 13.32 -26.282505 2.63e-07 2MASX J21145735+0527483 318.7390 5.4633 846.10 13.389 -26.248108 3.80e-07 2MASX J21082698+0811032 317.1124 8.1842 629.96 12.818 -26.17855 2.09e-07 2MASX J21104382+0450527 317.6825 4.8479 811.92 13.412 -26.13556 4.01e-07 2MASX J21141482+0644183 318.5617 6.7384 884.61 13.632 -26.101768 2.27e-07 2MASX J21103115+0658277 317.6298 6.9744 774.34 13.354 -26.090672 4.70e-07 2MASX J21114509+0726560 317.9379 7.4488 779.98 13.413 -26.047419 3.54e-07 2MASX J21080192+0652462 317.0081 6.8794 749.31 13.341 -26.03231 2.62e-07 2MASX J21172667+0309342 319.3611 3.1595 947.08 13.862 -26.019924 3.69e-07 Table: Top 20 galaxies in NED that fall in the 90% probability volume for S200129m sorted by 2MASS absolute K-band magnitude. Column descriptions are as follows. name: galaxy name. ra: RA (J2000, decimal degrees). dec: Dec (J2000, decimal degrees). distmpc: galaxy distance (Mpc). k_m_k20fe: the 2MASS apparent magnitude. M_Ks: the absolute K-band magnitude derived using the 'DistMpc' column. dP_dV: the 3D probability density per cubic megaparsec at the position of each galaxy. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26940 SUBJECT: LIGO/Virgo S200129m: no counterpart candidates in the Swift/BAT observations DATE: 20/01/29 22:49:08 GMT FROM: Amy Lien at GSFC A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (NASA/GSFC), D. M. Palmer (LANL), 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-ASDC), S. Emery (UCL-MSSL), P. A. Evans (U. Leicester), P. Giommi (ASI), C. Gronwall (PSU), D. Hartmann (Clemson U.), J. A. Kennea (PSU), N. Klingler (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 (U. of Birmingham), 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 (U. Toronto), 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 S200129m (LIGO/VIRGO Collaboration GCN Circ. 26926), where T0 is the LVC trigger time (2020-01-29T06:54:58.435 UTC). The center of the BAT field of view (FOV) at T0 is RA = 73.019 deg, DEC = 49.562 deg, and the roll angle is 287.138 deg. The BAT FOV (>10% partial coding) covers 0.00% of the integrated LVC localization probability, and 0.00% 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 astrophysical 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. The large structure seen ~T-250 s to ~T-50 is due to noisy detectors. 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 ~ 1.75e-07 x 10^-7 erg/s/cm^2. The flux limit calculation for this event only uses light curves from T0 +/- 50 s to exclude the interval with the large noise structure. 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 ~ 54.32 Mpc. Event data are available from T0-44.83 s to T0+45.21 s. No significant detections (above our typical image threshold of ~ 6.5 to 7 sigma) are found in the 15-350 keV images created using intervals of T0-0.1 to T0+0.1 s, T0-2 s to T0+8 s, and the whole event data range. BAT retains decreased, but significant, sensitivity to rate increases for gamma-ray events outside of its FOV. About 100.00% 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/S200129m/web/source_public.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26941 SUBJECT: LIGO/Virgo S200129m: Upper limits from CALET observations. DATE: 20/01/30 05:22:04 GMT FROM: Yuta Kawakubo at Louisiana State U./CALET M. L. Cherry (LSU), 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), 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 S200129m T0 = 2020-01-29 06:54:58.435 UT (The LIGO Scientific Collaboration and Virgo Collaboration, GCN Circ. 26926), the CALET Gamma-ray Burst Monitor (CGBM) high voltages were off (from T0-31 min to T0+1 min). The CALET Calorimeter (CAL) was operating in the high energy trigger mode at the trigger time of S200129m. Using the CAL data, we have searched for gamma-ray events in the 10-100 GeV band from -60 sec to +60 sec from the GW trigger time and found no candidates in the overwrap region with the LIGO-Virgo high probability localization region. The 90% upper limit of CAL is 5.7 x 10^-5 erg/cm^2/s (10-100 GeV) when the summed LIGO-Virgo probability reaches 5%. The CAL FOV was centered at RA = 288.7 deg, DEC = -34.3 deg at T0. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 26979 SUBJECT: LIGO/Virgo S200129m: Upper limits from Konus-Wind observations DATE: 20/02/03 19:36:33 GMT FROM: Anna Ridnaia at Ioffe Institute A. Ridnaia, S. Golenetskii, R.Aptekar, D. Frederiks, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, 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 S200129m (2020-01-29 06:54:58.435 UTC, hereafter T0; LIGO/Virgo Collaboration GCN Circ. 26926). No triggered KW GRBs happened between ~3 days before and ~1 day after T0. The closest waiting-mode GRB was observed ~23 hours after T0. Using waiting-mode data within the interval T0 +/- 100 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 7.9x10^-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 2.0x10^-7 erg/cm^2/s (20 - 1500 keV, 2.944 s scale). All the quoted values are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 27026 SUBJECT: LIGO/Virgo S200129m: Upper limits from Insight-HXMT/HE observations DATE: 20/02/09 12:29:42 GMT FROM: YaoGuang Zheng at IHEP Y. G. Zheng, C. Cai, Y. F. Du, W. C. Xue, Q. Luo, S. Xiao, Q. B. Yi, Y. Huang, C. K. Li, G. Li, X. B. 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 S200129m event (GCN #26926), trigger time 2020-01-29T06:54:58.435 UTC. At T0, about 97% 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=318.34 deg, DEC=4.57 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: 8.1e-08 erg cm^-2 10 s: 3.5e-07 erg cm^-2 Band model 2 (alpha=-1.0, beta=-2.3, Ep=230 keV): 1 s: 1.4e-07 erg cm^-2 10 s: 6.1e-07 erg cm^-2 Band model 3 (alpha=-0.0, beta=-1.5, Ep=1000 keV): 1 s: 5.4e-07 erg cm^-2 10 s: 1.9e-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.