TITLE:   GCN CIRCULAR
NUMBER:  36344
SUBJECT: LIGO/Virgo/KAGRA S240428dr: Updated Sky localization
DATE:    24/04/29 13:30:56 GMT
FROM:    Divyajyoti NLN <divyajyoti.nln@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 Virgo Observatory (V1) data around the time of the compact binary merger (CBC) candidate S240428dr (GCN Circular ***CITE ORIGINAL GCN ID, e.g. 25012***). 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/S240428dr

For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 186 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 831 +/- 145 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