Can Astrophysical Gamma-Ray Sources Mimic Dark Matter Annihilation in Galactic Satellites?

The nature of the cosmic dark matter is unknown. The most compellinghypothesis is that dark matter consists of weakly interacting massive particles(WIMPs) in the 100 GeV mass range. Such particles would annihilate in thegalactic halo, producing high-energy gamma rays which might be detectable ingamma ray telescopes such as the GLAST satellite. We investigate the ability ofGLAST to distinguish between WIMP annihilation sources and astrophysicalsources. Focusing on the galactic satellite halos predicted by the cold darkmatter model, we find that the WIMP gamma-ray spectrum is nearly unique;separation of the brightest WIMP sources from known source classes can be donein a convincing way by including spectral and spatial information. CandidateWIMP sources can be further studied with Imaging Atmospheric CerenkovTelescopes. Finally, Large Hadron Collider data might have a crucial impact onthe study of galactic dark matter.Comment: 4 pages, 5 figures, Accepted for publication in ApJ Letter