TITLE:   GCN CIRCULAR
NUMBER:  31670
SUBJECT: IceCube-220303A - IceCube observation of a high-energy neutrino candidate track-like event
DATE:    22/03/03 20:49:24 GMT
FROM:    Dr. Massimiliano Lincetto at Ruhr-Universitaet Bochum  <lincetto@astro.rub.de>

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

On 2022-03-03 at 18:00:07.62 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 0.54 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/136385_7450363.amon), more
sophisticated reconstruction algorithms have been applied offline, with
the direction refined to:

Date: 2022-03-03
Time:  18:00:07.62
RA: +267.80 (+1.50/-1.17 deg  90% PSF containment) J2000
Dec: +11.42 (+0.89/-1.14 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 or 3FHL catalog sources in the 90% uncertainty
region. The nearest gamma-ray sources in either catalog are 4FGL
J1745.5+1017 at RA: 266.40 deg, Dec: 10.30 deg and 4FGL J1751.5+0938
(OT 081) at RA: 267.88 deg, Dec: 9.65 (in J2000 coordinates, both 1.78
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