TITLE: GCN CIRCULAR NUMBER: 34797 SUBJECT: IceCube-231004A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 23/10/04 15:46:15 GMT FROM: Massimiliano Lincetto at Ruhr-Universitaet Bochum <lincetto@astro.ruhr-uni-bochum.de> The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 2023-10-04 at 14:39:41.18 UT IceCube detected a track-like event with a high probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_GOLD alert stream. The average astrophysical neutrino purity for Gold alerts is 50%. This alert has an estimated false alarm rate of 0.4490 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/138415_56188508.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 2023-10-04 Time: 14:39:41.18 UT RA: 143.79 (+1.10, -1.01 deg 90% PSF containment) J2000 Dec: -25.04 (+1.03, -1.21 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. There are no Fermi 4FGL-DR4 or 3FHL catalog sources in the 90% uncertainty region of the event. The nearest gamma-ray source in either catalog is 4FGL J0927.2+2454 at RA: 141.82 deg, Dec: -24.90 deg (1.79 deg away from the best-fit alert position). 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 View this GCN Circular online at https://gcn.nasa.gov/circulars/34797. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...