{
  "bibcode": "2019GCN.25497....1L",
  "body": "The LIGO Scientific Collaboration and the Virgo Collaboration report:\n\nWe identified the compact binary merger candidate S190828j during\nreal-time processing of data from LIGO Hanford Observatory (H1), LIGO\nLivingston Observatory (L1), and Virgo Observatory (V1) at 2019-08-28\n06:34:05.756 UTC (GPS time: 1251009263.756). The candidate was found\nby the GstLAL [1], CWB [2], PyCBC Live [3], MBTAOnline [4], and SPIIR\n[5] analysis pipelines.\n\nS190828j is an event of interest because its false alarm rate, as\nestimated by the online analysis, is 8.5e-22 Hz, or about one in 1e14\nyears. The event's properties can be found at this URL:\nhttps://gracedb.ligo.org/superevents/S190828j\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, there is strong\nevidence against the lighter compact object having a mass < 3 solar\nmasses (HasNS: <1%). Using the masses and spins inferred from the\nsignal, there is strong evidence against matter outside the final\ncompact object (HasRemnant: <1%).\n\nOne sky map is available at this time and can be retrieved from the\nGraceDB event page:\n * bayestar.fits.gz, an updated localization generated by BAYESTAR\n[6], distributed via GCN notice about 16 minutes after the candidate\n\nFor the bayestar.fits.gz sky map, the 90% credible region is 603 deg2.\nMarginalized over the whole sky, the a posteriori luminosity distance\nestimate is 2276 +/- 538 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] 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] Adams et al. CQG 33, 175012 (2016)\n [5] Qi Chu, PhD Thesis, The University of Western Australia (2017)\n [6] Singer & Price PRD 93, 024013 (2016)",
  "circularId": 25497,
  "createdOn": 1566976660000,
  "email": "olivier.minazzoli@ligo.org",
  "subject": "LIGO/Virgo S190828j: Identification of a GW compact binary merger candidate",
  "submitter": "Olivier Minazzoli at LIGO Virgo Collaboration  <olivier.minazzoli@ligo.org>",
  "eventId": "LIGO/Virgo S190828j"
}