Search for dark matter satellites using fermi-LAT

Abstract

Numerical simulations based on the δCDM 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 γ -ray emission expected from the annihilation ofweakly interactingmassive particle (WIMP) darkmatter. Some dark matter satellites are expected to have hard γ -ray spectra, finite angular extents, and a lack of counterparts at other wavelengths. We sought to identify LAT sources with these characteristics, focusing on γ -ray spectra consistent with WIMP annihilation through the b-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 GeVWIMP annihilating through the b-b channel. © 2012 The American Astronomical Society. All rights reserved.