TITLE:   GCN CIRCULAR
NUMBER:  29120
SUBJECT: IceCube-201222A: IceCube observation of a high-energy neutrino candidate event
DATE:    20/12/22 02:35:14 GMT
FROM:    Erik Blaufuss at U. Maryland/IceCube  <blaufuss@umd.edu>

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

On 20/12/22 at 00:56:16.14 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 1.008 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/134818_73718836.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 20/12/22
Time: 00:56:16.14 UT
RA:  206.37 (+0.90  -0.80 deg  90% PSF containment) J2000
Dec: 13.44 (+0.55 -0.38  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-LAT 4FGL or 3FHL sources inside the 90% localization region. The closest source is 4FGL J1353.3+1434 located at RA 208.34 deg and Dec 14.58 deg (J2000), at a distance of 2.22  degrees from the best-fit location.

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