TITLE:   GCN CIRCULAR
NUMBER:  35219
SUBJECT: LIGO/Virgo/KAGRA S231129ac: Updated Sky localization
DATE:    23/11/29 20:43:19 GMT
FROM:    Michael Puerrer at University of Rhode Island <mpuerrer@uri.edu>

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 S231129ac (GCN Circular 35211). 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/S231129ac

For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 3089 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 3964 +/- 1513 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/.

After parameter estimation by RapidPE-RIFT [2], the updated classification of the GW signal, in order of descending probability is BBH (99%), Terrestrial (1%), NSBH (<1%), or BNS (<1%).

 [1] Ashton et al. ApJS 241, 27 (2019) and Morisaki et al. arXiv:2307.13380 (2023)
 [2] Rose et al. arXiv:2201.05263 (2022) and Pankow et al. PRD 92, 023002 (2015)