TITLE: GCN CIRCULAR NUMBER: 35462 SUBJECT: IceCube-Cascade 231230A: Upper limits from a search for additional neutrino events in IceCube DATE: 24/01/02 20:32:16 GMT FROM: Jessie Thwaites at IceCube/U Wisc-Madison <thwaites@wisc.edu> 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 231230A (https://gcn.gsfc.nasa.gov/notices_amon_icecube_cascade/138802_36470430.amon) in a time range of 1000 seconds centered on the alert event time (2023-12-30 09:33:26.570 UTC to 2023-12-30 09:50:06.570 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 231230A. 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 231230A ranges from 1.3e-01 to 3.3e-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 2e+05 GeV. A subsequent search was performed including 2 days of data centered on the alert event time (2023-12-29 09:41:46.570 UTC to 2023-12-31 09:41:46.570 UTC). In this case, we report a p-value of 0.10, 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 231230A ranges from 1.5e-01 to 3.4e-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) View this GCN Circular online at https://gcn.nasa.gov/circulars/35462. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...