TITLE:   GCN CIRCULAR
NUMBER:  36932
SUBJECT: IceCube-240725A - IceCube observation of a high-energy neutrino candidate track-like event 
DATE:    24/07/25 12:54:07 GMT
FROM:    A. Zegarelli at Ruhr University Bochum <azegarelli@icecube.wisc.edu>

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

On 2024-07-25 at 05:11:37.93 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 0.9 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/139685_1723093.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 2024-07-25
Time:  05:11:37.93 UT
RA: 60.95 (+3.69, -2.81 deg 90% PSF containment) J2000
Dec: 49.31 (+2.48, -2.80 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 is one Fermi 4FGL-DR4 or 3FHL catalog source in the 90% uncertainty region. The nearest gamma-ray source in either catalog is 4FGL J0359.6+5057 at RA: 59.92 deg, Dec: 50.96 deg J2000 (1.8 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