Analysis of the Very Inner Milky Way Dark Matter Distribution and Gamma-Ray Signals

TL;DR

This paper investigates whether dark matter annihilation could explain gamma-ray signals from the Galactic Center, considering various density profiles and effects like black hole spikes and star scattering.

Contribution

It evaluates the impact of different dark matter density profiles and black hole effects on gamma-ray signals, offering new insights into the Galactic Center's dark matter distribution.

Findings

Dark matter spikes can enhance gamma-ray flux to match observations.

Certain density profiles explain the gamma-ray spectral cutoff.

Black hole effects influence the spatial distribution of gamma-ray signals.

Abstract

We analyze the possibility that the HESS gamma-ray source at the Galactic Center could be explained as the secondary flux produced by annihilation of TeV Dark Matter (TeVDM) particles with locally enhanced density, in a region spatially compatible with the HESS observations themselves. We study the inner 100 pc considering (i) the extrapolation of several density profiles from state-of-the-art N-body + Hydrodynamics simulations of Milky Way-like galaxies, (ii) the DM spike induced by the black hole, and (iii) the DM particles scattering off by bulge stars. We show that in some cases the DM spike may provide the enhancement in the flux required to explain the cut-off in the HESS J1745-290 gamma-ray spectra as TeVDM. In other cases, it may helps to describe the spatial tail reported by HESS II at angular scales < 0.54 degrees towards Sgr A.