GCN Circular 21223

M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (IFIC & APC), D.
  Dornic (CPPM/CNRS), A. Kouchner (APC/Universite Paris Diderot), T.
  Pradier (IPHC/Universite de Strasbourg) report on behalf of the ANTARES
  Collaboration:

  Using on-line data from the ANTARES detector, we have performed a
  follow-up analysis of the recently reported LIGO/Virgo G288732 event
  using the initial LIGO Bayestar probability map at event time (LVC
  GCN Circ. 21221
Not found
 
 
). The ANTARES visibility at the time of the alert
  together with the 90% contour of the probability map are shown
  in: https://www.cppm.in2p3.fr/~dornic/events/G288732/G288732.png (gwantares/
  ANT@GW28). Considering the location probability provided by the LIGO
  collaboration, there is a 55% chance that the GW emitter was in the
  ANTARES field of view.

  No up-going muon neutrino candidate events were recorded within the 90%
  contour during a +/- 500s time-window centered on the G288732 event
  time. The expected number of atmospheric background events in the
  region visible by ANTARES is ~2.4e-2 in the +/- 500s time window. An
  extended search during +/- 1 hour gives no up-going neutrino
  coincidence.

  An estimate of the upper limit on the associated neutrino fluence will
  be sent in a subsequent circular.

  ANTARES, being installed in the Mediterranean Deep Sea, is the largest
  neutrino detector in the Northern Hemisphere.  It 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 a
  large fraction of the Southern sky.