TITLE:   GCN CIRCULAR
NUMBER:  38243
SUBJECT: LIGO/Virgo/KAGRA S241114bi: Updated Sky localization and EM Bright Classification
DATE:    24/11/15 19:53:57 GMT
FROM:    Charlie Hoy at University of Portsmouth <charlie.hoy@port.ac.uk>

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

We have conducted further analysis of the LIGO Livingston Observatory (L1) and Virgo Observatory (V1) data around the time of the compact binary merger (CBC) candidate S241114bi (GCN Circular 38228). 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/S241114bi

Based on posterior support from parameter estimation [1], under the assumption that the candidate S241114bi is astrophysical in origin, the probability that at least one of the compact objects is consistent with a neutron star mass (HasNS) is <1%. [2] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [2] Both HasNS and HasRemnant consider the support of several neutron star equations of state for maximum neutron star mass. The probability that either of the binary components lies between 3 and 5 solar masses (HasMassGap) is 2%.

For the Bilby.offline0.multiorder.fits,0 sky map, the 90% credible region is 10127 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 752 +/- 195 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
 [2] Chatterjee et al. ApJ 896, 54 (2020) doi:10.3847/1538-4357/ab8dbe