GCN Circular 37600
Subject
LIGO/Virgo/KAGRA S240922df: Updated Sky localization
Date
2024-09-24T15:16:34Z (16 days ago)
From
Aaron Zimmerman at U. of Texas at Austin <aaron.zimmerman@utexas.edu>
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 S240922df (GCN Circular 37587). 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/S240922df
For the Bilby.multiorder.fits,0 sky map, the 90% credible region is well fit by an ellipse with an area of 120 deg2 described by the following DS9 region (right ascension, declination, semi-major axis, semi-minor axis, position angle of the semi-minor axis):
icrs; ellipse(20h34m, -18d27m, 14.32d, 2.66d, 51.24d)
Marginalized over the whole sky, the a posteriori luminosity distance estimate is 1175 +/- 262 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