Search for Dark Matter Satellites using the FERMI-LAT

TL;DR

This study used the Fermi-LAT gamma-ray telescope to search for dark matter satellites predicted by cosmological simulations, but found no candidates, thus constraining dark matter particle properties.

Contribution

First comprehensive gamma-ray search for dark matter satellites using Fermi-LAT data, providing constraints on WIMP annihilation cross sections.

Findings

No viable dark matter satellite candidates found.

Framework established for interpreting null results in context of simulations.

Constraints placed on WIMP annihilation cross section.

Abstract

Numerical simulations based on the Lambda-CDM model of cosmology predict a large number of as yet unobserved Galactic dark matter satellites. We report the results of a Large Area Telescope (LAT) search for these satellites via the gamma-ray emission expected from the annihilation of weakly interacting massive particle (WIMP) dark matter. Some dark matter satellites are expected to have hard gamma-ray spectra, finite angular extents, and a lack of counterparts at other wavelengths. We sought to identify LAT sources with these characteristics, focusing on gamma-ray spectra consistent with WIMP annihilation through the $b \bar b$ channel. We found no viable dark matter satellite candidates using one year of data, and we present a framework for interpreting this result in the context of numerical simulations to constrain the velocity-averaged annihilation cross section for a conventional 100 GeV WIMP annihilating through the $b \bar b$ channel.