Search for GeV gamma-ray emission from clusters of galaxies studied by TeV telescopes

TL;DR

This paper investigates GeV gamma-ray emission from galaxy clusters by analyzing Fermi data, providing upper limits for clusters previously studied by Cherenkov telescopes, to better understand their non-thermal components.

Contribution

It presents the first combined analysis of Fermi archival data for galaxy clusters with existing Cherenkov telescope upper limits, enhancing constraints on gamma-ray emission.

Findings

Established upper limits on GeV gamma-ray emission from multiple galaxy clusters.

Compared Fermi data with Cherenkov telescope results to refine non-thermal emission constraints.

Provided insights into cosmic ray confinement in galaxy clusters.

Abstract

A cluster of galaxies is a huge system bounded by gravitation, and cosmic rays are thought to be confined in the system, thus it should contain much non-thermal components. Many theories predict significant gamma-ray emission that could be detectable by state-of-the-art gamma-ray telescopes. Some clusters have already been studied by using Fermi gamma-ray space telescope in the GeV band and Cherenkov telescopes in the TeV band, but most clusters are not studied in both energy bands. Here I present results on GeV gamma-ray emission from clusters of galaxies which have been given upper limits by Cherenkov telescopes using Fermi archival data.