Untangling the Complexity in the Galactic Centre: a way to understand the origin of the gamma-ray emission from the inner Galaxy

Abstract

The origin of the high-energy gamma-ray emission from the Milky Way center is still unclear and debated because of the impact of systematics afflicting the measurements from current experiments. Several theories and phenomenological models attempt to explain the intricate panorama. The presence of a PeVatron in the Central Molecular Zone or in its vicinity, the contribution of the hard-component of the diffuse gamma-ray emission, and dark matter annihilation scenario are among the most promising mechanisms for describing the observed excess. The development of increasingly precise models able to reproduce the measured gamma-ray emission is the challenge for the scientific community in view of the next generation telescopes. A detailed treatment of phenomenological models for the dubbed Cosmic Rays Sea (CR-sea) characterized by different configurations is scrutinized in comparison with the observed spectrum in the inner Galaxy, using DRAGON and GAMMASKY codes.