TITLE: GCN CIRCULAR NUMBER: 39943 SUBJECT: IceCube-250330A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 25/03/30 11:02:08 GMT FROM: Giacomo Sommani at Ruhr-Universität Bochum gsommani@icecube.wisc.edu
The IceCube Collaboration (http://icecube.wisc.edu/) reports:
On 2025-03-30 08:31:06.33 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. The average astrophysical neutrino purity for Bronze alerts is 30%. This alert has an estimated false alarm rate of 1.7612 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection.
After the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon_g_b/140729_49427574.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:
Date: 2025-03-30 Time: 08:31:06.33 UT RA: 307.53 (+0.57, -0.47 deg 90% PSF containment) J2000 Dec: 11.07 (+0.45, -.47 deg 90% PSF containment) J2000
We encourage follow-up by ground and space-based instruments to help identify a possible astrophysical source for the candidate neutrino.
No known gamma-ray sources listed in the Fermi 4FGL-DR4 or 3FHL catalogs are located within the 90% uncertainty region of the event.
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
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