{
"subject": "LIGO/Virgo/KAGRA S231018cb: One counterpart neutrino candidate event from an IceCube neutrino search",
"submittedHow": "web",
"bibcode": "2023GCN.34838....1I",
"createdOn": 1697681185039,
"circularId": 34838,
"submitter": "Erik Blaufuss at University of Maryland, College Park ",
"body": "IceCube Collaboration (http://icecube.wisc.edu/) reports:\n\nWe have performed a search for track-like muon neutrino events detected by IceCube consistent with the sky localization of the low-significance gravitational-wave candidate event S231018cb in a time range of 1000 seconds centered on the alert event time (2023-10-18T23:40:06 UTC to 2023-10-18T23:56:46 UTC) [1,2] . \nDuring this time period IceCube was collecting good quality data. A single hypothesis test \nwas conducted, using a Bayesian approach to quantify the joint GW + neutrino event significance, which assumes a binary merger scenario and accounts for known astrophysical priors, such as GW source distance, in the statistical significance estimation [3]. \n\nOne track-like event is found in spatial and temporal coincidence with the gravitational-wave \nCandidate S231018cb calculated from the map circulated in the S231018cb-2-Preliminary notice. This represents an overall p-value of 0.003 for the Bayesian search. The p-value \nmeasures the consistency of the observed track-like events with the known atmospheric backgrounds for this single map (not accounting for statistical trials from multiple GW events). \n\nFurther details are available at https://gcn.nasa.gov/missions/icecube and at https://roc.icecube.wisc.edu/public/LvkNuTrackSearch.\n\nProperties of the coincident events are shown below:\n\n dt(s) RA(deg) Dec(deg) Angular uncertainty(deg) p-value(Bayesian)\n-----------------------------------------------------------------------------------------------------\n-24.13 170.53 +11.11 0.53 0.0031\n\nwhere:\ndt = Time of track event minus time of GW trigger (sec)\nAngular uncertainty = Angular uncertainty of track event: the radius of a circle \n representing 90% CL containment by area.\np-value = the p-value for this specific track event from this search.\n\nThe IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the \ngeographic South Pole, Antarctica. The IceCube realtime alert point of contact can be \nreached at roc@icecube.wisc.edu\n\n[1] M. G. Aartsen et al 2020 ApJL 898 L10\n[2] Abbasi et al. Astrophys.J. 944 (2023) 1, 80\n[3] I. Bartos et al. 2019 Phys. Rev. D 100, 083017\n"
}