GCN Circular 31252
Subject
IceCube-211216A: No neutrino counterpart candidates in ANTARES search
Date
2021-12-17T09:28:31Z (2 years ago)
From
Antoine Kouchner at ANTARES Collaboration <kouchner@apc.in2p3.fr>
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 recently reported track event IceCube-211216A (GCN #31241 <https://gcn.gsfc.nasa.gov/gcn3/31241.gcn3>). At the time of the alert, the reconstructed origin was -8.4 degrees below the horizon for ANTARES.
No up-going muon neutrino candidate events were recorded within the 90% error box of the IceCube event during a +/- 1h time-window centered on the IceCube event time, and over which the potential source remained visible from [T-60min, T+51min] (95%). This leads to a preliminary 90% confidence level upper limit on the muon-neutrino fluence from a point source of 16 GeV.cm^-2 over the energy range 5 TeV ��� 5 PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and 49 GeV.cm^-2 (1 TeV - 450 TeV) for an E^-2.5 spectrum.
A search over an extended time window of +/- 1 day has also yielded no detection (41% visibility).
ANTARES <http://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.