Search for Gamma-ray Emission from Dark Matter Annihilation in the Large Magellanic Cloud with the Fermi Large Area Telescope

TL;DR

This study uses five years of Fermi LAT data to search for gamma-ray signals from dark matter annihilation in the Large Magellanic Cloud, setting bounds on dark matter properties with robust astrophysical modeling.

Contribution

It provides the first comprehensive dark matter annihilation search in the LMC using updated gamma-ray models and rotation curve analysis for dark matter distribution.

Findings

No significant gamma-ray excess detected.

Placed competitive upper limits on dark matter annihilation cross section.

Confirmed astrophysical sources explain most gamma-ray emission.

Abstract

At a distance of 50 kpc and with a dark matter mass of $\sim10^{10}$ M$_{\odot}$, the Large Magellanic Cloud (LMC) is a natural target for indirect dark matter searches. We use five years of data from the Fermi Large Area Telescope (LAT) and updated models of the gamma-ray emission from standard astrophysical components to search for a dark matter annihilation signal from the LMC. We perform a rotation curve analysis to determine the dark matter distribution, setting a robust minimum on the amount of dark matter in the LMC, which we use to set conservative bounds on the annihilation cross section. The LMC emission is generally very well described by the standard astrophysical sources, with at most a $1-2\sigma$ excess identified near the kinematic center of the LMC once systematic uncertainties are taken into account. We place competitive bounds on the dark matter annihilation cross section as a function of dark matter particle mass and annihilation channel.