TITLE:   GCN CIRCULAR
NUMBER:  31692
SUBJECT: IceCube-220306A - IceCube observation of a high-energy neutrino candidate track-like event 
DATE:    22/03/06 05:13:34 GMT
FROM:    Erik Blaufuss at U. Maryland/IceCube  <blaufuss@umd.edu>

The IceCube Collaboration (http://icecube.wisc.edu/) reports:

On 2022-03-06 at 03:46:37.06 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 0.45 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/136392_25495567.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 2022-03-06
Time:  03:46:37.06 UT
RA: 314.82 (+0.54/-0.52 deg  90% PSF containment) J2000
Dec: +8.61 (+0.47/-0.55 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-DR2 or 3FHL catalog sources in the 90% uncertainty region. The nearest gamma-ray source in the 4FGL-DR2 catalog is 4FGL J2101.3+0912 at RA: 315.35 deg, Dec: 9.20 deg (in J2000 coordinates, 0.79 deg away from the best-fit event 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