Search for Astronomical Neutrinos from Blazar TXS0506+056 in Super-Kamiokande

TL;DR

This study searched for astronomical neutrinos from blazar TXS0506+056 using Super-Kamiokande data spanning over two decades, finding no significant excess but setting upper limits on neutrino fluxes.

Contribution

First comprehensive search for neutrinos from TXS0506+056 with Super-Kamiokande, providing constraints on neutrino fluxes in the GeV to TeV range.

Findings

No significant neutrino excess detected.

Upper limits established on electron and muon neutrino fluxes.

Data spanning from 1996 to 2018 used for analysis.

Abstract

We report a search for astronomical neutrinos in the energy region from several GeV to TeV in the direction of the blazar TXS0506+056 using the Super-Kamiokande detector following the detection of a 100 TeV neutrino from the same location by the IceCube collaboration. Using Super-Kamiokande neutrino data across several data samples observed from April 1996 to February 2018 we have searched for both a total excess above known backgrounds across the entire period as well as localized excesses on smaller time scales in that interval. No significant excess nor significant variation in the observed event rate are found in the blazar direction. Upper limits are placed on the electron and muon neutrino fluxes at 90\% confidence level as $6.03 \times 10^{-7}$ and $4.52 \times 10^{-7}$ to $9.26 \times 10^{-10}$ [${\rm erg}/{\rm cm}^2/{\rm s}$], respectively.