TITLE: GCN CIRCULAR NUMBER: 19885 SUBJECT: Search for counterpart to IceCube-160814A with ANTARES DATE: 16/08/31 20:02:23 GMT FROM: Damien Dornic at CPPM,France D. Dornic (CPPM/CNRS), A. Coleiro (APC/Universite Paris Diderot), D. Turpin (CPPM/IRAP/CNRS) 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 (HESE) neutrino IceCube-160814A (AMON IceCube HESE 58537957 128340). The reconstructed origin was 25.9 degrees below the horizon for ANTARES, with this position remaining below the horizon from -3.3h, +13h around the time of the alert. Thus ANTARES had a high sensitivity to any neutrinos from the same region. 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 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 (68% visibility probability). This yields a preliminary 90% upper limit on the muon-neutrino fluence from a point source of 15.7 GeV.cm^-2 over the energy range 2.8 TeV-3.1PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and 43.0 GeV.cm^-2 (0.4-280 TeV) for an E^-2.5 spectrum.