TITLE:   GCN CIRCULAR
NUMBER:  34896
SUBJECT: LIGO/Virgo/KAGRA S231028bg: Updated Sky localization
DATE:    23/10/28 21:40:40 GMT
FROM:    Christopher P L Berry at LVK Collaboration <christopher.berry@ligo.org>

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

We have conducted further analysis of the LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) data around the time of the compact binary merger (CBC) candidate S231028bg (GCN Circular 34895). 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/S231028bg

For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 1207 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 4221 +/- 923 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/userguide/.

 [1] Ashton et al. ApJS 241, 27 (2019) and Morisaki et al. arXiv:2307.13380 (2023)