{
  "bibcode": "2019GCN.24237....1L",
  "body": "The LIGO Scientific Collaboration and the Virgo Collaboration report:\n\nWe identified the compact binary merger candidate S190426c during\nreal-time processing of data from LIGO Hanford Observatory (H1), LIGO\nLivingston Observatory (L1), and Virgo Observatory (V1) at 2019-04-26\n15:21:55.337 UTC (GPS time: 1240327333.337). The candidate was found\nby the GstLAL [1], MBTAOnline [2], PyCBC Live [3], and SPIIR [4]\nanalysis pipelines.\n\nS190426c is an event of interest because its false alarm rate, as\nestimated by the online analysis, is 1.9e-08 Hz, or about one in 1\nyear, 7 months. The event's properties can be found at this URL:\n\nhttps://gracedb.ligo.org/superevents/S190426c\n\nThe classification of the GW signal, in order of descending\nprobability, is BNS (49%), MassGap (24%), Terrestrial (14%), NSBH\n(13%), or BBH (<1%).\n\nAssuming the candidate is astrophysical in origin, there is strong\nevidence for the lighter compact object having a mass < 3 solar\nmasses (HasNS: >99%). Using the masses and spins inferred from the\nsignal, there is strong evidence for matter outside the final compact\nobject (HasRemnant: >99%).\n\nTwo skymaps are available at this time and can be retrieved from the\nGraceDB event page:\n* bayestar.fits.gz, the preliminary sky localization generated by\n  BAYESTAR [5], distributed via GCN notice about 25 minutes after\n  the candidate,\n* bayestar1.fits.gz, an updated localization distributed via GCN\n  notice about an hour after the candidate. This is the preferred\n  skymap at this time.\n\nFor the bayestar1.fits.gz skymap, the 90% credible region is 1262\ndeg2. Marginalized over the whole sky, the a posteriori luminosity\ndistance estimate is 375 +/- 108 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/><https://emfollow.docs.ligo.org/userguide/>.\n\n[1] Messick et al. PRD 95, 042001 (2017)\n[2] Adams et al. CQG 33, 175012 (2016)\n[3] Nitz et al. PRD 98, 024050 (2018)\n[4] Qi Chu, PhD Thesis, The University of Western Australia (2017)\n[5] Singer & Price PRD 93, 024013 (2016)\n\n[GCN OPS NOTE(30apr19): Per author's request, the double spacing was removed.]",
  "circularId": 24237,
  "createdOn": 1556297104000,
  "email": "deep@uwm.edu",
  "subject": "LIGO/Virgo S190426c: Identification of a GW compact binary merger candidate",
  "submitter": "Deep Chatterjee at University of Wisconsin, Milwaukee  <deep@uwm.edu>",
  "eventId": "LIGO/Virgo S190426c"
}