TITLE:   GCN CIRCULAR
NUMBER:  37599
SUBJECT: LIGO/Virgo/KAGRA S240920dw: Updated Sky localization
DATE:    24/09/24 14:28:19 GMT
FROM:    lucy.thomas@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 S240920dw (GCN Circular 37571). 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/S240920dw

For the Bilby.multiorder.fits,0 sky map, the 90% credible region is 135 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 977 +/- 160 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