GCN Circular 32449
Subject
IceCube Astrotrack Bronze 136918_45252263.amon is likely background
Date
2022-08-08T16:42:17Z (3 years ago)
From
Marcos Santander at U. Alabama/IceCube <jmsantander@ua.edu>
The IceCube Collaboration (http://icecube.wisc.edu/) reports:
On 2022-08-08 at 07:59:57.263 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_Bronze alert stream (https://gcn.gsfc.nasa.gov/notices_amon_g_b/136918_45252263.amon). The average astrophysical neutrino purity for Bronze alerts is 30%. This alert has an estimated false alarm rate of 1.88 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection.
Upon further examination of the light deposition pattern of this event in the detector, and in particular due to the presence of light deposition in its veto region, it is likely that it was caused by a down-going atmospheric (background) muon rather than by a high-energy neutrino.
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