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arXiv · 1510.04518

Study of the VHE diffuse emission in the central 200 pc of our Galaxy with H.E.S.S

A. Lemiere·R. Terrier·L. Jouvin·V. Marandon·B. Khelifi
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Abstract

The very high energy emission from the Galactic Center Ridge was revealed by the High Energy Stereoscopic System (H.E.S.S.) in 2006, after subtraction of the point sources HESS J1745-290, possibly associated with Sgr A$^\star$, and HESS J1747$-$281, associated with the composite supernova remnant G0.9$+$0.1. The hard spectrum of the Ridge emission and its spatial correlation with the local gas density suggest that the emission is due to collisions of multi-TeV cosmic rays with the dense clouds of interstellar gas present in this region. The much larger H.E.S.S. dataset (250 hrs) that is now available from this region and the improved analysis method dedicated to the detection of faint emission allow us to reconsider the characterization of this gamma-ray emission in the central 200 pc of our Galaxy through a detailed morphology study. To test the various contributions to the total gamma-ray emission, we use a 2D maximum likelihood approach that allows to constrain a phenomenological model of the signal. We discuss the nature of the various components, and their implication on the cosmic-ray distribution in the central region of our Galaxy. Finally, we will reveal an additional source in this region and will discuss its potential nature.

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A. Lemiere, R. Terrier, L. Jouvin, V. Marandon, B. Khelifi. 2015-10-15. Study of the VHE diffuse emission in the central 200 pc of our Galaxy with H.E.S.S. https://arxiv.org/abs/1510.04518

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