TITLE: GCN CIRCULAR NUMBER: 26049 SUBJECT: HAWC-191019A: No Neutrino Counterpart detected with ANTARES DATE: 19/10/20 21:16:05 GMT FROM: Antoine Kouchner at ANTARES Collaboration Alexis Coleiro (APC/Univ 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 recently reported HAWC-191019A alert (GCN 26037).
No up-going muon neutrino candidate events were detected within 3 degrees from the event coordinates over a time window of [T0-11min, T0+1h] where T0 is the time of the HAWC alert, and during which the potential source remained visible in the up-going field of view of ANTARES. A search over an extended time window of +1 day has also yielded no detection (35% visibility).
This leads to a preliminary 90% confidence level upper limit on the muon-neutrino radiant fluence from a point source of about 90 GeV.cm^-2 over the energy range 6 TeV – 6 PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and about 110 GeV.cm^-2 (1 TeV GeV - 550 TeV) for an E^-2.5 spectrum, computed for the time of the Swift Busrt Alert.
ANTARES 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.