Skip to main content
Circulars over Kafka event name backfill. See news and announcements

GCN Circular 40128

Subject
AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-250409A
Date
2025-04-09T12:52:44Z (15 days ago)
From
Hugo Ayala at Pennsylvania State University <hgayala@psu.edu>
Via
Web form
The AMON,  IceCube, and HAWC collaborations report:

The AMON NuEm stream channel found a coincidence alert from the
IceCube online neutrino selection + HAWC daily monitoring analysis.
The analysis looks for IceCube neutrino events -mostly atmospheric
in origin- around the position and transit time of a HAWC cluster of
likely gamma rays, as identified in the integrated observations from
a single transit, in this case having a duration of 6.06 hours.

The HAWC transit interval starts from 2025/04/09 04:21:14 UT  to
2025/04/09 10:39:53 UT. A total of 6.3 hrs of integrated HAWC time. 


The location of the coincidence is reported as
RA (J2000): 212.8 deg
Dec (J2000): 17.2 deg
Location uncertainty (50% containment): 0.25 deg (statistical only).
Location uncertainty (90% containment): 0.46 deg (statistical only).

The false alarm rate (FAR) of this coincidence is 1.05 per year.
We encourage follow-up observations of the alert region contingent on
the availability of resources and interest, given the quoted FAR.

The source 4FGL J1406.9+1643 is the closest to the best position 
of the coincidence, with a distance of around 1deg. 

AMON seeks to perform a real-time correlation analysis of the
high-energy signals across all known astronomical messengers. More
information about AMON can be found in https://www.amon.psu.edu/
Information on the IceCube collaboration: http://icecube.wisc.edu/
Information on the HAWC collaboration: https://www.hawc-observatory.org

Looking for U.S. government information and services? Visit USA.gov