Density of dark matter in the Milky Way

Abstract

Although several discoveries have proved the gravitational effects of dark matter (DM) on various astrophysical objects, its origin remains one of the main puzzles in physics. These observations can be explained by adding a new particle to the Standard Model that is weakly interacting, massive, stable, and non-baryonic. One of the main characteristics of DM in question, beyond its exact particle nature, is its density in the Universe. In this paper, we use the latest data for the local DM density, total DM mass, and rotation curves in the Milky Way to estimate the density profile of these elusive particles in our Galaxy. We find the density profile parameters that match the current data and analyze the density of the stellar bulge and gas and star in the disk. We show that the stellar bulge dominates the Galactic dynamic for distances below a few kiloparsecs (kpc), the disk plays the most important role at intermediate distances, and DM explains rotation data beyond a few tens of kpc. Finally, we settle on a local DM density of about 0.5-0.7 GeV/ to fit the data well, regardless of the exact function we use to model the density profile.