TITLE: GCN CIRCULAR NUMBER: 24981 SUBJECT: IceCube-190704A - IceCube observation of a high-energy neutrino candidate event DATE: 19/07/04 20:49:46 GMT FROM: Marcos Santander at U. Alabama/IceCube The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 19/07/04 at 18:48:52.25 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 1.00 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/gcn/notices_amon_g_b/132792_60166398.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 19/07/04 Time: 18:48:52.25 UT RA: 161.85 (+2.16 -4.33 deg 90% PSF containment) J2000 Dec: 27.11 (+1.81 -1.83 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 is one unassociated Fermi 4FGL source lying within the 50% uncertainty region, 4FGL J1049.8+2741, at RA: 162.46 deg, Dec: 27.68 deg (0.8 deg away from the best-fit event position). There are no other Fermi 3FHL or 4FGL catalogue sources within the 90% contour. 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 _______________________________ Marcos Santander Assistant Professor Department of Physics & Astronomy 317B Gallalee Hall University of Alabama Tuscaloosa, AL 35487 +1 (205) 348 4863