Towards a realistic astrophysical interpretation of the Galactic center excess

Daniele Gaggero, Marco Taoso, Alfredo Urbano, Mauro Valli, Piero Ullio

Published 2015-07-22Version 1

A spherical-symmetric gamma-ray emission from the central region of the Galaxy has been recently identified in Fermi-LAT data, and initially associated to dark matter particle annihilations. Guided by the evidence for a high gas density in the inner kpc of the Galaxy correlated with a very large Supernova rate, and hence with ongoing cosmic-ray acceleration, we investigate instead the possibility of addressing this excess in terms of ordinary cosmic-ray sources and standard steady-state diffusion. We introduce the new ingredient in the context of the template-fitting algorithm, treating the new contribution as correlated to the conventional Inverse Compton emission. We analyze in detail the overall goodness of the fit of our framework, and perform a detailed direct comparison against data examining profiles in different directions.