# Searching for Gamma-Ray Emission from Reticulum II by Fermi-LAT

## TL;DR

This study reanalyzed Fermi-LAT data for Reticulum II, a dwarf galaxy, finding no significant gamma-ray emission and setting upper limits on dark matter annihilation cross sections.

## Contribution

It provides a detailed reanalysis of gamma-ray data for Reticulum II, treating it as an extended source, and establishes new upper limits on dark matter annihilation.

## Key findings

- No significant gamma-ray emission detected from Reticulum II.
- Set upper limits on dark matter annihilation cross section.
- Reanalyzed Fermi-LAT data considering spatial extension.

## Abstract

Recently, many new dwarf spheroidal satellites (dSphs) have been discovered by the Dark Energy Survey (DES). These dSphs are ideal candidates for probing for gamma-ray emissions from dark matter (DM) annihilation. However, no significant signature has been found by the Fermi-LAT dSph observations. In this work, we reanalyze the Fermi-LAT Pass 8 data from the direction of Reticulum II, where a slight excess has been reported by some previous studies. We treat Reticulum II (DES J0335.6-5403) as a spatially extended source, and and that no significant gamma-ray signature is observed. Based on this result, we set upper-limits on the DM annihilation cross section.