{
  "submitter": "Will Farr <will.farr@stonybrook.edu>",
  "subject": "LIGO/Virgo/KAGRA S250204ax: Updated Sky localization",
  "body": "The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report:\n\nWe 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 S250204ax (GCN Circular 39137). 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:\n\nhttps://gracedb.ligo.org/superevents/S250204ax\n\nFor the Bilby.multiorder.fits,0 sky map, the 90% credible region is 318 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 2056 +/- 690 Mpc (a posteriori mean +/- standard deviation).\n\nFor 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/.\n\n [1] Ashton et al. ApJS 241, 27 (2019) doi:10.3847/1538-4365/ab06fc and Morisaki et al. (2023) arXiv:2307.13380",
  "bibcode": "2025GCN.39143....1L",
  "createdOn": 1738688809741,
  "format": "text/plain",
  "submittedHow": "web",
  "circularId": 39143,
  "eventId": "LIGO/Virgo/KAGRA S250204ax"
}