{
  "bibcode": "2015GCN.18728....1L",
  "body": "The LIGO Scientific Collaboration and Virgo report:\n\nThe online gstlal CBC analysis, which is sensitive to binary coalescence\nevents from systems containing neutron stars and/or black holes,\nidentified candidate G211117 during real-time processing of data from\nLIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) at\n2015-12-26 03:38:53.648 UTC (GPS time: 1135136350.648).\n\nThe candidate was identified by an expanded low-latency pipeline\nconfiguration that is sensitive to stellar-mass BNS, NSBH, and BBH\nmergers. G211117 is an event of interest because its false alarm rate, as\ndetermined by the online analysis, passed our stated alert threshold of\n~1/month. The event's properties can be found at this URL:\n\nhttps://gracedb.ligo.org/events/G211117\n\nIf confirmed as astrophysical, the system contains at least one and most\nlikely two black holes.\n\nThe candidate was below the threshold for detection by the low-latency\nun-modeled burst searches. However, manual offline analysis with Coherent\nWaveBurst (cWB) recovered a candidate with consistent timing and\namplitude, designated G211182:\n\nhttps://gracedb.ligo.org/events/G211182\n\nTwo sky maps are available at this time and can be retrieved from the\nGraceDB event pages:\n\n * bayestar.fits.gz, an initial localization generated by the BAYESTAR\n   pipeline based on the CBC analysis about 2 minutes after the event. The\n   probability is concentrated in two long, thin arcs. The 50% credible\n   region spans about 430 deg2 and the 90% region about 1400 deg2. This is\n   the preferred sky map at this time.\n\n * skyprobcc_cwb.fits, generated from the cWB offline analysis about six\n   hours after the event. The area supported by this sky map is\n   qualitatively very similar to and essentially a superset of the\n   BAYESTAR sky map, with a 90% credible area of 2200 deg2.",
  "circularId": 18728,
  "createdOn": 1451237985000,
  "email": "leo.p.singer@nasa.gov",
  "subject": "LIGO/Virgo G211117: Identification of a GW CBC Candidate",
  "submitter": "Leo Singer at NASA/GSFC  <leo.p.singer@nasa.gov>",
  "eventId": "LIGO/Virgo G211117"
}