TITLE:   GCN CIRCULAR
NUMBER:  27871
SUBJECT: IceCube-200530A: No ANTARES neutrino counterpart
DATE:    20/05/31 08:00:43 GMT
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. <br> <br>  

Using data from the ANTARES detector, we have performed a follow-up analysis of the recently reported single track-like event IceCube-200530A (GCN 27865< https://gcn.gsfc.nasa.gov/gcn3/27865.gcn3 <https://gcn.gsfc.nasa.gov/gcn3/27865.gcn3>>). The original reconstructed origin was on the edge of the ANTARES field of view for upward going events (-0.04 degrees below Its horizon). <br> <br>
No muon neutrino candidate events were recorded in a 3 deg cone centered on the location of the IceCube event coordinates (accounting for the reported uncertainties) during a +/- 1h time-window centered on the IceCube event time. <br><br>

This leads to a preliminary conservative 90% confidence level upper limit on the muon-neutrino fluence from a point source of about 80 GeV.cm^-2 over the energy range 6.2 TeV – 6.0 PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and about 110 GeV.cm^-2 (1.0 TeV - 560 TeV) for an E^-2.5 spectrum.  A search over an extended time window of +/- 1 day has also yielded no detection (34% visibility). <br><br>
ANTARES <http://antares.in2p3.fr/ <http://antares.in2p3.fr/> <http://antares.in2p3.fr/ <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.