TITLE:   GCN CIRCULAR
NUMBER:  26230
SUBJECT: LIGO/Virgo S191110af: No neutrino counterpart candidate in ANTARES search
DATE:    19/11/11 12:43:15 GMT
FROM:    Antoine Kouchner at ANTARES Collaboration  <kouchner@apc.in2p3.fr>

M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (APC/Universite de Paris), M. Colomer (APC/Universite de Paris), D. Dornic (CPPM/CNRS), A. Kouchner (APC/Universite de Paris), 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 S191110af event using the 90% contour of the Initial CWB probability map provided by the GW interferometers (GCN#26222). The ANTARES visibility at the time of the alert, together with the 50% and 90% contours of the probability map are shown at gw191110af_preliminary.png <https://www.cppm.in2p3.fr/~dornic/gw191110af_preliminary.png>. Considering the location probability provided by the LIGO/Virgo collaborations, there is a 56.0% chance that the GW emitter was in the ANTARES **upgoing** field of view at the time of the alert. No up-going muon neutrino candidate events were recorded in the ANTARES sky during a ±500s time-window centered on the time 2019-11-10 23:06:44 and in the 90% contour of the S191110af event. The expected number of atmospheric background events in the region visible by ANTARES is 4.5e-04 in the ± 500s time window. An extended search during ± 1 hour gives no up-going muon neutrino coincidence. The expected number of atmospheric background events in the region visible by ANTARES is 3.3e-03 in this larger time window.

Moreover, no increase of the event rate compatible with an excess of MeV neutrinos from a Galactic core-collapse supernova was detected within +/-1h from the GW trigger time.

ANTARES is the largest undersea neutrino detector, installed in the Mediterranean Sea, and it is primarily sensitive to 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.