TITLE:   GCN CIRCULAR
NUMBER:  43421
SUBJECT: IceCube-260115A - IceCube observation of a high-energy neutrino candidate track-like event
DATE:    26/01/15 20:05:03 GMT
FROM:    A. Zegarelli at Ruhr University Bochum <azegarelli@icecube.wisc.edu>

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

On 26-01-15 at 17:32:35.71 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 2.0497 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/141917_80302474.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:

Date: 26-01-15
Time: 17:32:35.71 UT
RA: 145.77 (+2.29/-1.77 deg 90% PSF containment) J2000
Dec: 12.41 (+1.18/-0.91 deg 90% PSF containment) J2000

As announced in GCN Circular 43419 (https://gcn.nasa.gov/circulars/43419), the probability distribution of the true neutrino direction, allowing the extraction of precise 90% containment regions around the best-fit direction, is now available. The corresponding link (for this alert https://roc-2.icecube.wisc.edu/public/alerts/IceCube-260115A_skymap_probdensity_multiorder.fits.gz) is provided through the GCN schema distributed via Kafka.
IceCube GCN notices for high-energy track alerts (Gold and Bronze) are now also distributed via Kafka and can be accessed through the Kafka topic 'gcn.notices.icecube.gold_bronze_track_alerts'.
Further details will be available soon at https://gcn.nasa.gov/missions/icecube.
Please note that the classical GCN stream will be deactivated in the near future.

No known gamma-ray sources listed in the Fermi 4FGL-DR4 or 3FHL catalogs are located within the 90% uncertainty region of this event.

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