[vsnet-grb-info 22423] LIGO/Virgo S190513bm: Identification of a GW compact binary merger candidate

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24522
SUBJECT: LIGO/Virgo S190513bm: Identification of a GW compact binary merger candidate
DATE:    19/05/13 21:37:24 GMT
FROM:    Marco Drago at GSSI  <marco.drago at gssi.it>

The LIGO Scientific Collaboration and the Virgo Collaboration report:


We identified the compact binary merger candidate S190513bm during

real-time processing of data from LIGO Hanford Observatory (H1), LIGO

Livingston Observatory (L1), and Virgo Observatory (V1) at 2019-05-13

20:54:28.747 UTC (GPS time: 1241816086.747). The candidate was found

by the GstLAL [1], CWB [2], MBTAOnline [3], and spiir [4] analysis

pipelines.


S190513bm is an event of interest because its false alarm rate, as

estimated by the online analysis, is 3.7e-13 Hz, or about one in 1e5

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


https://gracedb.ligo.org/superevents/S190513bm


The classification of the GW signal, in order of descending

probability, is BBH (94%), MassGap (5%), NSBH (<1%), Terrestrial

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


Assuming the candidate is astrophysical in origin, there is strong

evidence against the lighter compact object having a mass < 3 solar

masses (HasNS: <1%). Using the masses and spins inferred from the

signal, there is strong evidence against matter outside the final

compact object (HasRemnant: <1%).


One skymap is available at this time and can be retrieved from the

GraceDB event page:

* bayestar.fits.gz, an updated localization generated by BAYESTAR

[5], distributed via GCN notice about 27 minutes after the candidate


For the bayestar.fits.gz skymap, the 90% credible region is 691 deg2.

Marginalized over the whole sky, the a posteriori luminosity distance

estimate is 1987 +/- 501 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] Klimenko et al. PRD 93, 042004 (2016)

[3] Adams et al. CQG 33, 175012 (2016)

[4] Qi Chu, PhD Thesis, The University of Western Australia (2017)

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