Fermi Gamma-ray Space Telescope

On the Origin of the Very-High-Energy Gamma-ray Emission of the Galactic Centre region

A. Viana
F. Aharonian, S. Gabici, E. Moulin, K. Kosack, R. D. Parsons, R. Tuffs, for the H.E.S.S. collaboration


The Galactic Centre region has been observed by the High Energy Stereoscopic System (H.E.S.S.) I array of ground-based Cherenkov telescopes since 2004 leading to the detection of the very high-energy (VHE, E > 100 GeV) gamma-?ray source HESS J1745-?290 spatially coincident with the supermassive black hole Sgr A*. Diffuse TeV gamma-ray emission has been detected along the Galactic Centre Ridge, most likely due to cosmic-ray interactions with dense gas of the Central Molecular Zone. We report here the results of a detailed spectral and morphological study of the Galactic Centre Ridge emission based on the full data set of 2004-2013 observations. The new results allow us to make a strong statement regarding the location and origin of the accelerator of the parent ultrarelativistic particles. We will discuss possible implications of the observed emission, in particular, in the context of large-scale diffuse emissions (Fermi bubbles and extraterrestrial neutrinos) and the origin of Galactic cosmic rays.