TITLE:   GCN CIRCULAR
NUMBER:  31986
SUBJECT: IceCube-220501A - IceCube observation of a high-energy neutrino candidate track-like event
DATE:    22/05/02 00:28:05 GMT
FROM:    Marcos Santander at U. Alabama/IceCube  <jmsantander@ua.edu>

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

On 2022-05-01 at 22:50:58.64 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 2.110 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/136588_56014830.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 2022-05-01
Time:  22:50:58.64 UT
RA: 311.57 (+0.82, -1.07 deg  90% PSF containment) J2000
Dec: 18.68 (+1.08, -0.92 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 known gamma-ray sources in the 90% containment region for the event. The nearest source in the 4FGL-DR3 Fermi-LAT catalog is 4FGL J2043.3+1711 (310.84 deg, 17.19 deg J2000, 1.65 deg away from the best-fit neutrino candidate 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