Searching for High-Energy Neutrino Emission from Galaxy Clusters with IceCube

TL;DR

This study used 9.5 years of IceCube data to search for neutrino emission from galaxy clusters, finding no significant signals but setting upper limits on their neutrino flux contribution.

Contribution

First stacking analysis of galaxy clusters with IceCube data, providing constraints on neutrino emission from these sources.

Findings

No significant neutrino emission detected from galaxy clusters.

Upper limits constrain cluster neutrino flux to less than 4.6% of IceCube diffuse flux.

Results limit the contribution of galaxy clusters to high-energy neutrino background.

Abstract

Galaxy clusters have the potential to accelerate cosmic rays (CRs) to ultra-high energies via accretion shocks or embedded CR acceleration sites. CRs with energies below the Hillas condition will be confined within the cluster and will eventually interact with the intracluster medium (ICM) gas to produce secondary neutrinos and $\gamma$ rays. Using 9.5 years of muon-neutrino track events from the IceCube Neutrino Observatory, we report the results of a stacking analysis of 1094 galaxy clusters, with masses $\gtrsim 10^{14}$ \(\textup{M}_\odot\) and redshifts between 0.01 and $\sim$1, detected by the {\it Planck} mission via the Sunyaev-Zeldovich (SZ) effect. We find no evidence for significant neutrino emission and report upper limits on the cumulative unresolved neutrino flux from massive galaxy clusters after accounting for the completeness of the catalog up to a redshift of 2, assuming three different weighting scenarios for the stacking and three different power-law spectra. Weighting the sources according to mass and distance, we set upper limits at $90\%$ confidence level that constrain the flux of neutrinos from massive galaxy clusters ($\gtrsim 10^{14}$ \(\textup{M}_\odot\)) to be no more than $4.6\%$ of the diffuse IceCube observations at 100~TeV, assuming an unbroken $E^{-2.5}$ power-law spectrum.