LIGO/Virgo S200311bg: Identification of a GW compact binary merger candidate
Abstract
We identified the compact binary merger candidate S200311bg during realtime processing of data from LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) at 20200311 11:58:53.398 UTC (GPS time: 1267963151.398). The candidate was found by the GstLAL [1], CWB [2], PyCBC Live [3], SPIIR [4], and MBTAOnline [5] analysis pipelines. S200311bg is an event of interest because its false alarm rate, as estimated by the online analysis, is 8.9e26 Hz, or about one in 1e18 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S200311bg 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 2 minutes after the candidate event time. * bayestar.fits.gz,1, an initial localization generated by BAYESTAR [6], distributed via GCN notice about 10 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 well fit by an ellipse with an area of 52 deg2 described by the following DS9 region (right ascension, declination, semimajor axis, semiminor axis, position angle of the semiminor axis): icrs; ellipse(00h08m, 07d27m, 8.54d, 1.98d, 72.86d) Marginalized over the whole sky, the a posteriori luminosity distance estimate is 924 +/ 188 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 <https://emfollow.docs.ligo.org/userguide/>. [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] Qi Chu, PhD Thesis, The University of Western Australia (2017) [5] Adams et al. CQG 33, 175012 (2016) [6] Singer & Price PRD 93, 024013 (2016)
 Publication:

GRB Coordinates Network
 Pub Date:
 March 2020
 Bibcode:
 2020GCN.27358....1L