GCN Circular 42550
Subject
LIGO/Virgo/KAGRA S251031cq: Updated Sky localization
Date
2025-11-03T14:27:10Z (2 days ago)
From
Colm Talbot at Princeton University <talbotcolm@gmail.com>
Via
Web form
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 S251031cq (GCN Circular 42529). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.multiorder.fits,0, distributed via GCN and SCiMMA notices, is available for retrieval from the GraceDB event page:
https://gracedb.ligo.org/superevents/S251031cq
For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 393 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 2129 +/- 714 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