GCN Circular 34057

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 230621A (https://gcn.gsfc.nasa.gov/notices_amon_icecube_cascade/138065_72143074.amon) in a time range of 1000 seconds centered on the alert event time (2023-06-21 01:47:30.360 UTC to 2023-06-21 02:04:10.360 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 230621A. 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 230621A ranges from 8.1e+00 to 1.4e+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 3e+04 GeV and 4e+06 GeV. 

A subsequent search was performed including 2 days of data centered on the alert event time (2023-06-20 01:55:50.360 UTC to 2023-06-22 01:55:50.360 UTC). In this case, we report a p-value of 0.80, 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 230621A ranges from 8.2e+00 to 1.4e+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)