Gamma rays from the Galactic Centre region: a review

TL;DR

This review summarizes recent advances in gamma-ray observations of the Galactic Centre, highlighting insights into high-energy particle acceleration, transport, and dark matter searches in this active and complex region.

Contribution

It provides a comprehensive overview of gamma-ray emission mechanisms and recent dark matter search results in the Galactic Centre across multiple energy bands.

Findings

Detection of gamma rays up to PeV energies from the GC

Constraints on dark matter particle properties from gamma-ray data

Evidence of high-energy particle acceleration in the Galactic nucleus

Abstract

During the last decades, increasingly precise astronomical observations of the Galactic Centre (GC) region at radio, infrared, and X-ray wavelengths laid the foundations to a detailed understanding of the high energy astroparticle physics of this most remarkable location in the Galaxy. Recently, observations of this region in high energy (HE, 10 MeV - 100GeV) and very high energy (VHE, > 100 GeV) gamma rays added important insights to the emerging picture of the Galactic nucleus as a most violent and active region where acceleration of particles to very high energies -- possibly up to a PeV -- and their transport can be studied in great detail. Moreover, the inner Galaxy is believed to host large concentrations of dark matter (DM), and is therefore one of the prime targets for the indirect search for gamma rays from annihilating or decaying dark matter particles. In this article, the current understanding of the gamma-ray emission emanating from the GC is summarised and the results of recent DM searches in HE and VHE gamma rays are reviewed.