{
  "subject": "LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate",
  "eventId": "LIGO/Virgo/KAGRA S241102br",
  "submittedHow": "web",
  "bibcode": "2024GCN.38043....1L",
  "createdOn": 1730552926628,
  "circularId": 38043,
  "submitter": "francesca.bucci@fi.infn.it",
  "format": "text/plain",
  "body": "The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report:\n\nWe identified the compact binary merger candidate S241102br during real-time processing of data from LIGO Hanford Observatory (H1), LIGO Livingston Observatory (L1), and Virgo Observatory (V1) at 2024-11-02 12:40:58.788 UTC (GPS time: 1414586476.788). The candidate was found by the cWB [1], cWB BBH [2], GstLAL [3], MBTA [4], PyCBC Live [5], and SPIIR [6] analysis pipelines.\n\nS241102br is an event of interest because its false alarm rate, as estimated by the online analysis, is 1.1e-41 Hz, or about one in 1e33 years. The event's properties can be found at this URL:\n\nhttps://gracedb.ligo.org/superevents/S241102br\n\nThe classification of the GW signal, in order of descending probability, is BBH (>99%), NSBH (<1%), Terrestrial (<1%), or BNS (<1%).\n\nAssuming the candidate is astrophysical in origin, the probability that the lighter compact object is consistent with a neutron star mass (HasNS) is <1%. [7] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [7] 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 14%.\n\nTwo sky maps are available at this time and can be retrieved from the GraceDB event page:\n * bayestar.multiorder.fits,0, an initial localization generated by BAYESTAR [8], distributed via GCN notice about 28 seconds after the candidate event time.\n * bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [8], distributed via GCN notice about 5 minutes after the candidate event time.\n\nThe preferred sky map at this time is bayestar.multiorder.fits,1. For the bayestar.multiorder.fits,1 sky map, the 90% credible region is well fit by an ellipse with an area of 47 deg2 described by the following DS9 region (right ascension, declination, semi-major axis, semi-minor axis, position angle of the semi-minor axis):\n   icrs; ellipse(23h00m, +40d28m, 7.08d, 2.10d, 96.84d)\nMarginalized over the whole sky, the a posteriori luminosity distance estimate is 354 +/- 63 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] Klimenko et al. PRD 93, 042004 (2016) doi:10.1103/PhysRevD.93.042004\n [2] T. Mishra et al. PRD 105, 083018 (2022) doi:10.1103/PhysRevD.105.083018\n [3] Tsukada et al. PRD 108, 043004 (2023) doi:10.1103/PhysRevD.108.043004 and Ewing et al. (2023) arXiv:2305.05625\n [4] Aubin et al. CQG 38, 095004 (2021) doi:10.1088/1361-6382/abe913\n [5] Dal Canton et al. ApJ 923, 254 (2021) doi:10.3847/1538-4357/ac2f9a\n [6] Chu et al. PRD 105, 024023 (2022) doi:10.1103/PhysRevD.105.024023\n [7] Chatterjee et al. ApJ 896, 54 (2020) doi:10.3847/1538-4357/ab8dbe\n [8] Singer & Price PRD 93, 024013 (2016) doi:10.1103/PhysRevD.93.024013\n"
}