{
  "bibcode": "2022GCN.31679....1I",
  "body": "The IceCube Collaboration (http://icecube.wisc.edu/) reports:\n\nOn 4 March 2022 at 17:44:12.21 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 0.58 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection.\n\nAfter the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon_g_b/136388_4701751.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:\n\nDate: 2022-03-04\nTime:  17:44:12.21 UT\nRA: 48.78 (+7.68/-6.24 deg  90% PSF containment) J2000\nDec: 4.48 (+5.91/-4.96 deg 90% PSF containment) J2000\n\nWe encourage follow-up by ground and space-based instruments to help identify a possible astrophysical source for the candidate neutrino.\n\nGiven the size of the 90% event containment region, many gamma-ray sources listed in the 4FGL-DR2 Fermi-LAT catalog are consistent with the best-fit candidate neutrino position. The \nsources 4FGL J0321.3+0425 is the closest, at 1.54 degrees from the best fit direction.\n\nThe large uncertainty region arises from the partially-contained nature of this event, being detected at the edge of the IceCube instrumented volume.  \n\nThe 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",
  "circularId": 31679,
  "createdOn": 1646420259000,
  "email": "blaufuss@umd.edu",
  "subject": "IceCube-220304A - IceCube observation of a high-energy neutrino candidate track-like event",
  "submitter": "Erik Blaufuss at U. Maryland/IceCube  <blaufuss@umd.edu>",
  "eventId": "IceCube-220304A"
}