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GCN Circular 34953

LIGO/Virgo/KAGRA S231106y: one counterpart neutrino candidate from IceCube neutrino searches
2023-11-06T16:07:24Z (5 months ago)
Erik Blaufuss at University of Maryland, College Park <>
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The IceCube Collaboration ( reports:

A search for track-like muon neutrino events detected by IceCube consistent with the sky localization of the low-significance gravitational wave candidate S231106y in a time range of 1000 seconds centered on the alert event time (2023-11-06 06:48:08 UTC to 2023-11-06 07:04:48 UTC) has been performed [1,2]. During this time period IceCube was collecting good quality data. One hypothesis test was conducted for this low-significance gravitational wave event. The search uses 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 significance estimate [3].

One track-like event was found in spatial and temporal coincidence with the gravitational-wave
candidate S231106y calculated from the map circulated by LVK as S231106y-2-Preliminary. This
represents an overall pre-trial p-value of 0.0090 for the Bayesian search.

The reported p-value here does not account for any trials correction (multiple hypotheses testing). The false alarm rate of this coincidence can be obtained by multiplying the p-value with the corresponding GW trigger rate. Further details are available at  and at

Properties of the coincident event(s) are shown below.

dt(s)	RA(deg)		Dec(deg)	Angular uncertainty(deg)  p-value(generic transient) p-value(Bayesian)
41.78   318.15     	69.01          6.54                        not applicable		0.0090

dt = Time of track event minus time of GW trigger (sec)
Angular uncertainty = Angular uncertainty of track event: the radius of a circle
 	representing 90% CL containment by area.
p-value = the p-value for this specific track event from each search.

The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the
geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be
reached at

[1] M. G. Aartsen et al 2020 ApJL 898 L10
[2] Abbasi et al. Astrophys.J. 944 (2023) 1, 80
[3] I. Bartos et al. 2019 Phys. Rev. D 100, 083017

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