[vsnet-grb-info 24616] LIGO/Virgo S200112r: Identification of a GW compact binary merger candidate

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26715
SUBJECT: LIGO/Virgo S200112r: Identification of a GW compact binary merger candidate
DATE:    20/01/12 16:27:18 GMT
FROM:    Erik Katsavounidis at MIT  <kats at ligo.mit.edu>

LIGO/Virgo S200112r: Identification of a GW compact binary merger candidate

The LIGO Scientific Collaboration and the Virgo Collaboration report:


We identified the compact binary merger candidate S200112r during

real-time processing of data from LIGO Livingston Observatory (L1) and

Virgo Observatory (V1) at 2020-01-12 15:58:38.094 UTC (GPS time:

1262879936.094). The candidate was found by the GstLAL [1] analysis

pipeline.


S200112r is an event of interest because its false alarm rate, as

estimated by the online analysis, is 1.3e-11 Hz, or about one in 1e3

years. The event's properties can be found at this URL:

https://gracedb.ligo.org/superevents/S200112r


The classification of the GW signal, in order of descending

probability, is BBH (>99%), Terrestrial (<1%), BNS (<1%), MassGap

(<1%), or NSBH (<1%).


Assuming the candidate is astrophysical in origin, the probability

that the lighter compact object has a mass < 3 solar masses (HasNS) is

<1%. Using the masses and spins inferred from the signal, the

probability of matter outside the final compact object (HasRemnant) is

<1%.


Two sky maps are available at this time and can be retrieved from the

GraceDB event page:

  * bayestar.fits.gz,0, an initial localization generated by BAYESTAR

[2], distributed via GCN notice about 2 minutes after the candidate

event time.

  * bayestar.fits.gz,1  -- identical to bayestar.fits.gz,0


The preferred sky map at this time is bayestar.fits.gz,1. For the

bayestar.fits.gz,1 sky map, the 90% credible region is 6199 deg2.

Marginalized over the whole sky, the a posteriori luminosity distance

estimate is 1136 +/- 320 Mpc (a posteriori mean +/- standard

deviation).


For further information about analysis methodology and the contents of

this alert, refer to the LIGO/Virgo Public Alerts User Guide

<https://emfollow.docs.ligo.org/userguide/>.


  [1] Messick et al. PRD 95, 042001 (2017)

  [2] Singer & Price PRD 93, 024013 (2016)