Tracking origins of gamma rays in the Milky Way galaxy by a Fermi-LAT all sky map

Abstract

Abstract We have used gamma ray data of an all sky map from Fermi-LAT to estimate a mathematical model of emission coefficient to find the origins of gamma rays in the Milky Way galaxy. The emission coefficient is defined for the first time by spherical and cylindrical distributions which are explained by dark matter annihilation and astrophysical sources, respectively. We have provided parameter values from our fitting by least chi-square method. Our parameters for cylindrical distribution are compatible with previous studies, except the thickness of the galactic disk which 10 times bigger than the previous studies since they have set the value of the thickness as 0.100 kpc for a thin cylindrical disk of the Milky Way galaxy but we have considered the whole range of latitude for the all sky map. It indicates that our model has provided a thicker galactic disk than the others. In addition, we have provided the parameter values of spherical distribution which we can apply to constrain properties of dark matter particles in the Milky Way galaxy for future studies.