TITLE:   GCN CIRCULAR
NUMBER:  37103
SUBJECT: IceCube-240808A - IceCube observation of a high-energy neutrino candidate track-like event 
DATE:    24/08/08 16:58:32 GMT
FROM:    A. Zegarelli at Ruhr University Bochum <azegarelli@icecube.wisc.edu>

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

On 2024-08-08 at 06:32:39.25 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 1.177 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/139735_13003768.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 2024-08-07
Time:  06:32:39.25 UT
RA: 55.77 (+5.86, -4.83 deg 90% PSF containment) J2000
Dec: 31.83 (+3.42, -3.91 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 twelve Fermi 4FGL-DR4 or 3FHL catalog sources in the 90% uncertainty region. The nearest gamma-ray source in either catalog is 4FGL J0341.9+3153c at RA: 55.49 deg, Dec: 31.90 deg J2000 (0.25 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