Search for high-energy gamma-ray emission from galaxies of the Local Group with Fermi/LAT

TL;DR

This study searches for high-energy gamma-ray emission from Local Group galaxies using Fermi/LAT data, finding no significant detections but establishing upper limits and discussing cosmic ray interactions.

Contribution

It provides the first systematic search for gamma-ray emission from Local Group galaxies and sets upper limits on their high-energy emission.

Findings

No significant gamma-ray detection from studied galaxies.

Upper limits on gamma-ray emission are established.

Results are discussed in the context of cosmic ray interactions.

Abstract

Normal galaxies begin to arise from the shadows at high energies, as can be seen with the discovery of high-energy gamma-ray emission from the Andromeda galaxy (M 31) by the Fermi /LAT collaboration. We present a study on the search for high-energy emission around galaxies of the Local Group. No significant detection is found from the objects studied here. Upper limits on the high-energy emission of nearby normal galaxies are derived, and we discuss them in the context of gamma-ray emission from cosmic ray interactions with the local interstellar medium in these galaxies.