{
"subject": "LIGO/Virgo S200311bg: Updated Sky Localization and EM Bright Classification",
"bibcode": "2020GCN.27382....1L",
"createdOn": 1584112375000,
"circularId": 27382,
"submitter": "Geoffrey Mo at MIT ",
"email": "gmo@mit.edu",
"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\nS200311bg (GCN Circular 27358).\nParameter estimation has been performed using LALInference [1] and a\nnew sky map, LALInference.fits.gz,0, distributed via GCN Notice, is\navailable for retrieval from the GraceDB event page:\n\nhttps://gracedb.ligo.org/superevents/S200311bg\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 well fit by\nan ellipse with an area of 34 deg2 described by the following DS9\nregion (right ascension, declination, semi-major axis, semi-minor\naxis, position angle of the semi-minor axis):\n icrs; ellipse(00h09m, -08d14m, 6.91d, 1.59d, 72.77d)\nMarginalized over the whole sky, the a posteriori luminosity distance\nestimate is 1115 +/- 175 Mpc (a posteriori mean +/- standard\ndeviation).\n\nBased on posterior support from parameter estimation [1], under the\nassumption that the candidate S200311bg is astrophysical in origin,\nthe probability that the lighter compact object has a mass < 3 solar\nmasses (HasNS) is <1%. Using the masses and spins inferred from the\nsignal, the probability of matter outside the final compact object\n(HasRemnant) is <1%.\n\nFor further information about analysis methodology and the contents of\nthis alert, refer to the LIGO/Virgo Public Alerts User Guide\n.\n\n [1] Veitch et al. PRD 91, 042003 (2015)"
}