33RD INTERNATIONAL COSMIC RAY CONFERENCE, RIO DE JANEIRO 2013 THE ASTROPARTICLE PHYSICS CONFERENCE Spectral analysis of the Galactic Center emission at very-high-energy gamma-

Abstract: The Galactic Centre region has been observed by the complete 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 coincident in position with the supermassive black hole Sgr A*. A TeV gamma-ray diffuse emision has been detected along the Galactic ridge, very likely to be related to cosmic-ray interactions in giant molecular clouds of the Central Molecular Zone. We report here on a spectral morphology study of the inner 50 pc of the Galactic Centre region using the full data set of 2004-2012 observations. The contamination from diffuse emission to HESS J1745-290 is subtracted which allows to recover the intrinsic spectrum of the central source. The intrinsic source spectrum is well described by a power-law spectrum with an exponential energy cut-off at ∼ 7 TeV