{
  "bibcode": "2020GCN.27193....1L",
  "body": "We identified the compact binary merger candidate S200225q during\nreal-time processing of data from LIGO Hanford Observatory (H1) and LIGO\nLivingston Observatory (L1) at 2020-02-25 06:04:21.397 UTC (GPS time:\n1266645879.397). The candidate was found by the PyCBC Live [1],\nCWB [2], MBTAOnline [3], GstLAL [4], and SPIIR [5] analysis pipelines.\n\nS200225q is an event of interest because its false alarm rate, as\nestimated by the online analysis, is 9.2e-09 Hz, or about one in 3\nyears. The event's properties can be found at this URL:\nhttps://gracedb.ligo.org/superevents/S200225q\n\nThe classification of the GW signal, in order of descending\nprobability, is BBH (96%), Terrestrial (4%), BNS (<1%), NSBH\n(<1%), or MassGap (<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 3 minutes after the candidate\nevent time.\n * bayestar.fits.gz,1, an initial localization generated by BAYESTAR\n[6], distributed via GCN notice about 11 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 668 deg2.\nMarginalized over the whole sky, the a posteriori luminosity distance\nestimate is 1234 +/- 341 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<https://emfollow.docs.ligo.org/userguide/>.\n\n [1] Nitz et al. PRD 98, 024050 (2018)\n [2] Klimenko et al. PRD 93, 042004 (2016)\n [3] Adams et al. CQG 33, 175012 (2016)\n [4] Messick et al. PRD 95, 042001 (2017)\n [5] Qi Chu, PhD Thesis, The University of Western Australia (2017)\n [6] Singer & Price PRD 93, 024013 (2016)",
  "circularId": 27193,
  "createdOn": 1582612692000,
  "email": "vvalsan@uwm.edu",
  "subject": "LIGO/Virgo S200225q: Identification of a GW compact binary merger candidate The LIGO Scientific Collaboration and the Virgo Collaboration",
  "submitter": "Vinaya Valsan at U. of Wisconsin Milwaukee  <vvalsan@uwm.edu>",
  "eventId": "LIGO/Virgo S200225q"
}