TITLE:   GCN CIRCULAR
NUMBER:  36703
SUBJECT: LIGO/Virgo/KAGRA S240618ah: Updated Sky localization
DATE:    24/06/19 21:37:35 GMT
FROM:    Michael J. Williams at University of Portsmouth <michael.williams@ligo.org>

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

We have conducted further offline analysis of the LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) data around the time of the compact binary merger (CBC) candidate S240618ah (GCN Circular 36689). Parameter estimation has been performed using Bilby [1] and a new sky map, Bilby.offline0.multiorder.fits,0, distributed via GCN Notice, is available for retrieval from the GraceDB event page:

https://gracedb.ligo.org/superevents/S240618ah

For the Bilby.offline0.multiorder.fits,0 sky map, the 90% credible region is 5116 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 5939 +/- 2437 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. (2023) arXiv:2307.13380