{
"subject": "LIGO/Virgo S200311bg: Identification of a GW compact binary merger candidate",
"bibcode": "2020GCN.27358....1L",
"createdOn": 1583929684000,
"circularId": 27358,
"submitter": "Geoffrey Mo at MIT ",
"email": "gmo@mit.edu",
"body": "The LIGO Scientific Collaboration and the Virgo Collaboration report:\n\nWe identified the compact binary merger candidate S200311bg during\nreal-time processing of data from LIGO Hanford Observatory (H1), LIGO\nLivingston Observatory (L1), and Virgo Observatory (V1) at 2020-03-11\n11:58:53.398 UTC (GPS time: 1267963151.398). The candidate was found\nby the GstLAL [1], CWB [2], PyCBC Live [3], SPIIR [4], and MBTAOnline\n[5] analysis pipelines.\n\nS200311bg is an event of interest because its false alarm rate, as\nestimated by the online analysis, is 8.9e-26 Hz, or about one in 1e18\nyears. The event's properties can be found at this URL:\nhttps://gracedb.ligo.org/superevents/S200311bg\n\nThe classification of the GW signal, in order of descending\nprobability, is BBH (>99%), Terrestrial (<1%), BNS (<1%), MassGap\n(<1%), or NSBH (<1%).\n\nAssuming the candidate is astrophysical in origin, the probability\nthat the lighter compact object has a mass < 3 solar masses (HasNS) is\n<1%. Using the masses and spins inferred from the signal, the\nprobability of matter outside the final compact object (HasRemnant) is\n<1%.\n\nTwo sky maps are available at this time and can be retrieved from the\nGraceDB event page:\n * bayestar.fits.gz,0, an initial localization generated by BAYESTAR\n[6], distributed via GCN notice about 2 minutes after the candidate\nevent time.\n * bayestar.fits.gz,1, an initial localization generated by BAYESTAR\n[6], distributed via GCN notice about 10 minutes after the candidate\nevent time.\n\nThe preferred sky map at this time is bayestar.fits.gz,1. For the\nbayestar.fits.gz,1 sky map, the 90% credible region is well fit by an\nellipse with an area of 52 deg2 described by the following DS9 region\n(right ascension, declination, semi-major axis, semi-minor axis,\nposition angle of the semi-minor axis):\n icrs; ellipse(00h08m, -07d27m, 8.54d, 1.98d, 72.86d)\nMarginalized over the whole sky, the a posteriori luminosity distance\nestimate is 924 +/- 188 Mpc (a posteriori mean +/- standard\ndeviation).\n\nFor further information about analysis methodology and the contents of\nthis alert, refer to the LIGO/Virgo Public Alerts User Guide\n.\n\n [1] Messick et al. PRD 95, 042001 (2017)\n [2] Klimenko et al. PRD 93, 042004 (2016)\n [3] Nitz et al. PRD 98, 024050 (2018)\n [4] Qi Chu, PhD Thesis, The University of Western Australia (2017)\n [5] Adams et al. CQG 33, 175012 (2016)\n [6] Singer & Price PRD 93, 024013 (2016)"
}