Addressing $\\gamma$-ray emissions from dark matter annihilations in 45 milky way satellite galaxies and in extragalactic sources with particle dark matter models

Abstract

This has been suggested that the dwarf satellite galaxies in the Milky Way may contain substantial amount of dark matter in them. These dark matters may undergo self-annihilation to produce $\\gamma$-rays. The satellite borne $\\gamma$-ray telescope such as Fermi-LAT reported the detection of $\\gamma$-rays from around 45 Dwarf Spheroidals (dSphs) of Milky Way. In this work, we consider a particle dark matter model and after studying its phenomenology, we calculate the $\\gamma$-ray fluxes of each of these 45 dSphs and compare our results with the upper bounds of mass vs annihilation cross-sections of dark matter provided by the Fermi-LAT collaboration. We calculate these fluxes by considering different dark matter density profiles and make a comparison between them. We also repeat our analysis with another dark matter candidate namely Kaluza-Klein (KK) dark matter inspired by extra-dimensional models. We make a critical comparison between the results obtained for each of these models vis-a-vis the observational results.