Limits on the Emission of Gamma Rays from M31 (The Andromeda Galaxy) with HAWC

TL;DR

This study searches for gamma-ray bubble structures in the Andromeda Galaxy using HAWC data, finding no significant emission and setting upper limits on possible flux.

Contribution

First analysis to set upper limits on TeV gamma-ray emission from Fermi-like bubbles in M31 using HAWC observations.

Findings

No significant gamma-ray emission detected from M31 bubbles.

Established upper limits on TeV flux from potential bubble structures.

Supports the absence of active gamma-ray emitting bubbles in M31 at current sensitivity.

Abstract

The detection of the Fermi Bubbles suggests that spiral galaxies such as the Milky Way can undergo active periods. Using gamma-ray observations, we can investigate the possibility that such structures are present in other nearby galaxies. We have analyzed the region around the Andromeda Galaxy (Messier Catalog M31) for signs of bubble-like emission using TeV gamma-ray data recorded by the High-Altitude Water Cherenkov Observatory. We fit a model consisting of two 6 kpc bubbles symmetric about and perpendicular to the M31 galactic plane and assume a power-law distribution for the gamma-ray flux. We compare the emission from these bubble regions to that expected from structures similar to the Fermi Bubbles found in the Milky Way. No significant emission was observed. We report upper limits on the TeV flux from Fermi Bubble structures in M31.