TITLE:   GCN CIRCULAR
NUMBER:  21867
SUBJECT: LIGO/Virgo G299232: Pierre Auger Observatory follow-up
DATE:    17/09/12 08:02:10 GMT
FROM:    Jaime Alvarez-Muniz at Pierre Auger Observatory  <jaime.alvarezmuniz@gmail.com>

J. Alvarez-Muniz, F. Pedreira, E. Zas (Univ. Santiago de Compostela, Spain),
K. H. Kampert & M. Schimp (Bergische Universitat, Wuppertal, Germany)
on behalf of the Pierre Auger Collaboration.

In response to the LIGO/Virgo GW trigger G299232
(GCN #21693, T0=2017-08-25, 13:13:37.983 UTC):

We searched for Ultra High Energy (UHE) neutrinos with energies
above ~ 1e17 eV in data collected with the Surface Detector (SD) of
the Pierre Auger Observatory in a [-500,500] second interval about
the LIGO-Virgo trigger G299232 as well as 1 day after it.

NO events survived the cuts applied to reject the background due to UHE
Cosmic Rays i.e. NO neutrino candidates were detected.

The field of view (fov) where the SD of Auger is sensitive to UHE neutrinos
(corresponding to inclined directions with respect to the vertical relative
to the ground) was coincident with only a small fraction of the most
updated
LIGO 90% localization region (bayestar-HLV.fits.gz) at the time T0 of the
merger alert. Some parts of the 90% region closest to the Northern
hemisphere
are never visible in the Auger fov.

The Pierre Auger Observatory is an UHE Cosmic Ray detector
located in the Mendoza Province in Argentina. It consists of an array
of Water Cherenkov detectors spread over a total surface of 3000 km^2
arranged in a triangular grid of 1.5 km side as well as Fluorescence
telescopes and other systems (see 10.1016/j.nima.2015.06.058
for more information).
For neutrino searches from GW events with Auger, please refer to:
https://journals.aps.org/prd/pdf/10.1103/PhysRevD.94.122007