[vsnet-grb-info 22535] LIGO/Virgo S190521r: No neutrino counterpart candidates in ANTARES search

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24634
SUBJECT: LIGO/Virgo S190521r: No neutrino counterpart candidates in ANTARES search
DATE:    19/05/21 09:28:58 GMT
FROM:    Damien Dornic at CPPM,France  <dornic at cppm.in2p3.fr>

M. Ageron (CPPM/CNRS), B. Baret (APC/CNRS), A. Coleiro (APC/Universite Paris Diderot), M. Colomer (APC/Universite Paris Diderot)), 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 S190521r event using the 90% contour of the bayestar probability map provided by the GW interferometers (GCN#24632). The ANTARES visibility at the time of the alert, together with the 50% and 90% contours of the probability map are shown at https://www.cppm.in2p3.fr/~dornic/events_runo3/S190521r.png. Considering the location probability provided by the LIGO/Virgo collaborations, there is a 30% 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 (2019-05-21 07:43:59 UT) and in the 90% contour of the S190521r event. The expected number of atmospheric background events in the region visible by ANTARES is 7.4e-5 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 5.3e-4 in this larger time window.

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.