TITLE: GCN CIRCULAR NUMBER: 25925 SUBJECT: LIGO/Virgo S190930t: No neutrino candidates at Pierre Auger Observatory DATE: 19/10/02 15:02:56 GMT FROM: Jaime Alvarez-Muniz at Pierre Auger Observatory J. Alvarez-Muniz, F. Pedreira, E. Zas (IGFAE & University of Santiago de Compostela, Spain), K. H. Kampert & M. Schimp (University of Wuppertal, Germany) on behalf of the Pierre Auger Collaboration. In response to: LIGO/Virgo GW trigger S190930t T0=2019-09-30 14:34:07 UTC We searched for Ultra-High-Energy (UHE) neutrinos in the data collected with the Surface Detector (SD) of the Pierre Auger Observatory in a [-500,500] second interval about the LIGO-Virgo trigger S190930t as well as in a 24 hr time interval following the event. The Observatory is mostly sensitive to neutrinos above ~ 1e17 eV. 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 PARTIALLY COINCIDENT (35.7%) with the LIGO/Virgo 90% localization region (bayestar.fits.gz,0) at the time T0 of the merger alert, achieving a MAXIMUM OVERLAP (36.1%) at approximately T0+17.5 hours. ------- 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 https://arxiv.org/abs/1906.07422