GCN Circular 35332
Subject
IceCube-231211A: Upper limits from a search for additional neutrino events in IceCube
Date
2023-12-13T22:08:40Z (a year ago)
From
Jessie Thwaites at IceCube/U Wisc-Madison <thwaites@wisc.edu>
Via
Web form
The IceCube Collaboration (http://icecube.wisc.edu/) reports:
IceCube has performed a search [1] for additional track-like muon neutrino events arriving from the direction of IceCube-231211A (https://gcn.nasa.gov/circulars/35328) in a time range of 1000 seconds centered on the alert event time (2023-12-11 00:39:11.790 UTC to 2023-12-11 00:55:51.790 UTC) during which IceCube was collecting good quality data. Excluding the event that prompted the alert, zero track-like events are found within the 90% containment region of IceCube-231211A. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-231211A is 1.3e-01 GeV cm^-2 in a 1000 second time window. 90% of events IceCube would detect from a source at this declination with an E^-2.5 spectrum have energies in the approximate energy range between 2e+02 GeV and 1e+05 GeV.
A subsequent search was performed including 2 days of data centered on the alert event time (2023-12-10 00:47:31.790 UTC to 2023-12-12 00:47:31.790 UTC). One track-like event is found to be within the 90% contour of the alert event. Its properties are shown in the table below. In this case, we report a p-value of 0.02, consistent with no significant excess of track events. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-231211A is 1.5e-01 GeV cm^-2 in a 2 day time window.
dt(s) RA(deg) Dec(deg) Angular uncertainty(deg)
-----------------------------------------------------------------------------------------------
64664 311.73 10.06 1.03
where:
dt = Time of track event minus time of alert event (sec)
Angular uncertainty = Angular uncertainty of track event: the radius of a circle
representing 90% CL containment by area
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] IceCube Collaboration, R. Abbasi et al., ApJ 910 4 (2021)