Comparison between Different Models for the Dark Matter Distribution in the Milky Way

Sammanfattning

Dark matter is one of the great mysteries in physics today, and while the nature of this matter is unknown, many theories suggest that dark matter consists of some yet undiscovered particles. Indirect detection of dark matter is the detection of annihilation or decay products from such dark matter particles. In this project, I have used Micromegas, a public software developed to calculate dark matter properties, to calculate the fluxes of photons and muon neutrinos produced by annihilation of dark matter in the galactic halo of the Milky Way. This has been done with the minimal supersymmetric standard model (MSSM) as a particle model, and for four different dark matter halo models: isothermal, Navarro-Frenk-White (NFW), Moore and Einasto. The goal was to analyse how the annihilation flux depends on the dark matter distribution. The results show that the Moore model predicts the highest fluxes of photons and muon neutrinos, followed by Einasto, NFW and isothermal. The shapes of the fluxes, a decrease in flux as the energy increases, seem to be similar for all four models; only the amount differs. This indicates that the distribution of dark matter might not affect the resulting shape of the flux of annihilation products very much. The level of flux seems to follow the amount of dark matter well: more dark matter in the region between our sun and the galactic centre gives a higher flux of annihilation products. It therefore seems likely that the biggest contributor to the annihilation fluxes is the amount of dark matter.