{
  "bibcode": "2020GCN.26807....1L",
  "body": "The LIGO Scientific Collaboration and the Virgo Collaboration report:\n\nWe have conducted further analysis of the LIGO Hanford Observatory\n(H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1)\ndata around the time of the compact binary merger (CBC) candidate\nS200115j (GCN Circular 26759). Parameter estimation has been performed\nusing LALInference [1] and a new sky map, LALInference.fits.gz,0,\ndistributed via GCN Notice, is available for retrieval from the\nGraceDB event page:\n\nhttps://gracedb.ligo.org/superevents/S200115j/files/\n\nThe preferred sky map at this time is LALInference.fits.gz,0. For the\nLALInference.fits.gz,0 sky map, the 90% credible region is 765 deg2.\nMarginalized over the whole sky, the a posteriori luminosity distance\nestimate is 340 +/- 79 Mpc (a posteriori mean +/- standard deviation).\n\nBased on posterior support from parameter estimation [1], under the\nassumption that the candidate is astrophysical in origin, the\nprobability that the lighter compact object has a mass < 3 solar\nmasses (HasNS) is >99%. Using the masses and spins inferred from the\nsignal, the probability of matter outside the final compact object\n(HasRemnant) is >99%.\n\nNote: the sequence of three Preliminary Notices on January 15, 2020\nfor this candidate was due to a manual change in the\n\"preferred event\". The MBTAOnline pipeline found the largest\nsignal-to-noise ratio (SNR) and thus provided the first preferred\nevent, as indicated in the first two Preliminary Notices. However, the\npreferred event was manually changed to a GstLAL trigger (with nearly\nthe same SNR) because of a possible discrepancy noted in the\nlow-latency Bayestar sky maps calculated for the two triggers. The\nthird Preliminary Notice reflected that change.\n\nFor further information about analysis methodology including\n�preferred events�, refer to the LIGO/Virgo Public Alerts User Guide\n<https://emfollow.docs.ligo.org/userguide/>.\n\n [1] Veitch et al. PRD 91, 042003 (2015)",
  "circularId": 26807,
  "createdOn": 1579287016000,
  "email": "deep@uwm.edu",
  "subject": "LIGO/Virgo S200115j: Updated Sky Localization and source properties",
  "submitter": "Deep Chatterjee at University of Wisconsin, Milwaukee  <deep@uwm.edu>",
  "eventId": "LIGO/Virgo S200115j"
}