{
  "bibcode": "2020GCN.26906....1L",
  "body": "The LIGO Scientific Collaboration and the Virgo Collaboration report:\n\nWe identified the compact binary merger candidate S200128d during\nreal-time processing of data from LIGO Hanford Observatory (H1) and\nLIGO Livingston Observatory (L1) at 2020-01-28 02:20:11.903 UTC (GPS\ntime: 1264213229.903). The candidate was found by the PyCBC Live [1],\nCWB [2], MBTAOnline [3], and GstLAL [4] analysis pipelines.\n\nS200128d is an event of interest because its false alarm rate, as\nestimated by the online analysis, is 1.6e-08 Hz, or about one in 1\nyear, 11 months. The event's properties can be found at this URL:\nhttps://gracedb.ligo.org/superevents/S200128d\n\nThe classification of the GW signal, in order of descending\nprobability, is BBH (97%), Terrestrial (3%), BNS (<1%), NSBH (<1%), or\nMassGap (<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[5], distributed via GCN notice about 3 minutes after the candidate\nevent time.\n ��* bayestar.fits.gz,1, an initial localization generated by BAYESTAR\n[5], distributed via GCN notice about 9 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 2521 deg2.\nMarginalized over the whole sky, the a posteriori luminosity distance\nestimate is 4031 +/- 1241 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] Singer & Price PRD 93, 024013 (2016)",
  "circularId": 26906,
  "createdOn": 1580180176000,
  "email": "kats@ligo.mit.edu",
  "subject": "LIGO/Virgo S200128d: Identification of a GW compact binary merger candidate",
  "submitter": "Erik Katsavounidis at MIT  <kats@ligo.mit.edu>",
  "eventId": "LIGO/Virgo S200128d"
}