GCN Circular 40194
Subject
IceCube-Cascade 250414A: Upper limits from a search for additional neutrino events in IceCube
Date
2025-04-21T20:59:33Z (2 days ago)
From
Sam Hori at IceCube/U Wisc-Madison <sahori@wisc.edu>
Via
email
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-Cascade 250414A (https://gcn.gsfc.nasa.gov/notices_amon_icecube_cascade/140790_14362468.amon) in a time range of 1000 seconds centered on the alert event time (2025-04-14 07:38:53.610 UTC to 2025-04-14 07:55:33.610 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-Cascade 250414A. 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-Cascade 250414A ranges from 1.3e-01 to 1.4e-01GeV 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 2e+05 GeV.
A subsequent search was performed including 2 days of data centered on the alert event time (2025-04-13 07:47:13.610 UTC to 2025-04-15 07:47:13.610 UTC). In this case, we report a p-value of 0.41, 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-Cascade 250414A ranges from 1.5e-01 to 1.6e-01 GeV cm^-2 in a 2 day time window.
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)