TITLE:   GCN CIRCULAR
NUMBER:  23218
SUBJECT: Search for counterpart to IceCube-180908A with ANTARES 
DATE:    18/09/10 07:38:51 GMT
FROM:    Damien Dornic at CPPM,France  <dornic@cppm.in2p3.fr>

Alexis Coleiro (APC) and Damien Dornic (CPPM)  report on behalf of the ANTARES Collaboration:

Using data from the ANTARES detector, we have performed a follow-up analysis of the recently reported single high-energy (EHE) neutrino IceCube-180908A (GCN 23214). The reconstructed origin was 40.7 degrees below the horizon for ANTARES. 

No up-going muon neutrino candidate events were recorded within three degrees of the IceCube event coordinates during a +/- 1h time-window centered on the IceCube event time. A search over an extended time window of +/- 1 day has also yielded no detection (52% visibility probability). 

This yields a preliminary 90% confidence level upper limit on the muon-neutrino fluence from a point source of 18 GeV.cm^-2 over the energy range 2.4 TeV - 2.6 PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and 36 GeV.cm^-2 (400 GeV - 250 TeV) for an E^-2.5 spectrum. 

ANTARES is the largest neutrino detector installed in the Mediterranean Sea, and is primarily sensitive to astrophysical neutrinos in the TeV-PeV energy range. At 10 TeV, the median angular resolution for muon neutrinos is below 0.5 degrees. In the range 1-100 TeV, ANTARES has a competitive sensitivity to this position in the sky.