TITLE:   GCN CIRCULAR
NUMBER:  37596
SUBJECT: LIGO/Virgo/KAGRA S240920bz: Updated Sky localization and Source Classification
DATE:    24/09/24 14:22:14 GMT
FROM:    jgolomb@caltech.edu

The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report:

We have conducted further analysis of the LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) data around the time of the compact binary merger (CBC) candidate S240920bz (GCN Circular 37562). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.multiorder.fits,0, distributed via GCN Notice, is available for retrieval from the GraceDB event page:

https://gracedb.ligo.org/superevents/S240920bz

For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 349 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1372 +/- 305 Mpc (a posteriori mean +/- standard deviation).

For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/.

 [1] Ashton et al. ApJS 241, 27 (2019) doi:10.3847/1538-4365/ab06fc and Morisaki et al. PRD 108, 123040 (2023) doi:10.1103/PhysRevD.108.123040