TITLE: GCN CIRCULAR NUMBER: 19772 SUBJECT: Search for counterpart to IceCube-160731A with ANTARES DATE: 16/08/05 06:20:35 GMT FROM: Damien Dornic at CPPM,France D. Dornic (CPPM/CNRS), A. Coleiro (APC/Universite Paris Diderot), 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 extremely high-energy (EHE) neutrino +IceCube-160731A (AMON IceCube HESE 128290 6888376). Its position is -28.1 degrees below the horizon for ANTARES which could yield to an up-going +event at the time of the event. ANTARES is the largest neutrino detector installed in the Mediterranean Sea 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 the best +sensitivity to this position in the sky. 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 on an extended time window of +/- 1 day has also yielded no detection (50% visibility probability). This yields a preliminary 90% upper limit on the fluence from a point source of 14 GeV.cm^-2 (2.8 TeV-3.1PeV, energy range corresponding to +5-95% of the energy distribution) and 27 GeV.cm^-2 (0.4-280 TeV) assuming a E^-2 and E^-2.5 power law spectrum, respectively. [GCN OPS NOTE(05aug16): Per operator, the double TITLE-block was removed.]