UC Santa Cruz

The nature of Dark Matter is one of the most significant outstanding questions in cosmology; current estimates are that over 80\% of the matter of the universe is composed of an invisible heavy particle whose nature is unknown. Numerical simulations of the evolution of structure in the universe, based on the Lambda CDM model of cosmology, predict that the mass of galaxies like the Milky Way are dominated by large DM halos extending far beyond the luminous disk, and that these halos are clumpy: they have a significant amount of mass in the form of “subhalos,” also called DM satellites.

A convenient candidate particle for DM is provided by Supersymmetry (SUSY), an extension of the Standard Model (SM) of particle physics which posits that each SM fermion has a partner SUSY boson, and vice versa. In many SUSY theories, the lightest supersymmetric particle (LSP) is stable and is its own antiparticle, pair-annihilating into gamma rays. The Fermi Large Area Telescope (LAT) has generated an active area of study in the search for this DM annihilation signal. The signal from DM satellites of the Milky Way would appear as gamma ray sources with no counterparts at other wavelengths, and would have a distinct spectrum and resolvable spatial extension. In this dissertation, we present results on the analysis of unassociated LAT sources, and what constraints can be set on different DM candidates in the case of a non-detection.