The Detectability of Neutralino Clumps via Atmospheric Cherenkov Telescopes

Abstract

High resolution N-body simulations have revealed the survival of considerable substructure within galactic halos. Assuming that the predicted dark matter clumps are composed of annihilating neutralinos, we examine their detectability via Atmospheric Cherenkov Telescopes (ACTs). Depending on their density profile, individual neutralino clumps should be observable via their gamma-ray continuum and line emissions. We find that the continuum signal is the most promising signal for detecting a neutralino clump, being significantly stronger than the monochromatic signals. Limits from the line detectability can help lift degeneracies in the supersymmetric (SUSY) parameter space. We show that by combining the observations of different mass clumps, ACTs can explore most of the SUSY parameter space. ACTs can play a complementary role to accelerator and gamma-ray satellite limits by exploring relatively large neutralino masses and less concentrated clumps. We develop a strategy for dark matter clump studies by future ACTs based on VERITAS specifications and encourage the development of techniques to identify primaries. This can reduce the background by an order of magnitude.