//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 30010 SUBJECT: AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEM-210515A and 210515B DATE: 21/05/15 03:15:53 GMT FROM: Hugo Ayala at Pennsylvania State University The AMON, IceCube, and HAWC collaborations report: The AMON NuEm stream channel found two coincidence alerts 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 hours. NuEM-210515A The HAWC transit interval starts from 05-14-2021 18:06:02 UT to 05-15-2021 00:20:43 UT (End of the HAWC transit time) The location of the coincidence is reported as RA (J2000): 93.64deg Dec (J2000): 14.66 deg Location uncertainty (50% containment): 0.15 deg (statistical only). Location uncertainty (90% containment): 0.27 deg (statistical only). The false alarm rate (FAR) of this coincidence is 3.93 per year. NuEM-210515B The HAWC transit interval starts from 05-14-2021 18:09:25 UT to 05-15-2021 00:19:27 UT (End of the HAWC transit time) The location of the coincidence is reported as RA (J2000): 93.93deg Dec (J2000): 12.51deg Location uncertainty (50% containment): 0.20 deg (statistical only). Location uncertainty (90% containment): 0.36 deg (statistical only). The false alarm rate (FAR) of this coincidence is 1.90 per year. We encourage follow-up observations of the alert region contingent on availability of resources and interest, given the quoted FAR. 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 of this analysis https://iopscience.iop.org/article/10.3847/1538-4357/abcaa4 Information on the IceCube collaboration: http://icecube.wisc.edu/ Information on the HAWC collaboration: https://www.hawc-observatory.org //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 30024 SUBJECT: AMON IC_HAWC NuEm-210515A / NuEm-210515B : No neutrino counterpart detected with ANTARES DATE: 21/05/16 07:47:41 GMT FROM: Antoine Kouchner at ANTARES Collaboration Alexis Coleiro (APC/Universite de Paris) and Damien Dornic (CPPM/CNRS) on behalf of the ANTARES Collaboration. Using data from the ANTARES detector, we have performed a follow-up analysis of the two recently reported AMON IC-HAWC coincidence alert NuEm-210515A and NuEm-210515B (https://gcn.gsfc.nasa.gov/gcn3/30010.gcn3). No up-going muon neutrino candidate events were detected within 3 degrees from the two coincidence coordinates over a time period [21h15 - 00h20 (+1) UTC] corresponding to 49.5% of the HAWC transit time mentioned in the AMON notice, during which the potential source remained visible in the up-going field of view of ANTARES. This leads to a preliminary 90% confidence level upper limit on the muon neutrino radiant fluence from a point source located at the coordinates of the coincidence as reported by AMON, of about 15 GeV.cm^-2 over the energy range 5 TeV - 4 PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and about 30 GeV.cm^-2 (1 - 400 TeV) for an E^-2.5 spectrum. These indicative limits have been computed for the end of the HAWC transit time. A search over an extended time window of +/-1 day has also yielded no detection (42% visibility). ANTARES (https://antares.in2p3.fr) is the largest undersea neutrino detector (Mediterranean Sea) and it is primarily sensitive to astrophysical neutrinos in the TeV-PeV energy range. At 10 TeV, the median angular resolution for muon neutrinos is about 0.5 degrees. In the range 1-100 TeV ANTARES has a competitive sensitivity to this position in the sky.