GCN Circular 34953

The IceCube Collaboration (http://icecube.wisc.edu/) 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 https://gcn.nasa.gov/missions/icecube  and at  https://roc.icecube.wisc.edu/public/LvkNuTrackSearch.
. 

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



where:
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 roc@icecube.wisc.edu


[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