We present a novel interpretation of the gamma-ray diffuse emission in the Galactic Center (GC) and the Central Molecular Zone (CMZ) regions. This is based on a scenario assuming a harder scaling of the diffusion coefficient with rigidity in the inner Galaxy which reproduces the radial dependence of the cosmic-ray (CR) spectral index recently inferred from Fermi-LAT. We compare our model with H.E.S.S. and (for the fist time in this context) with PASS8 Fermi-LAT data which allows to cover the entire energy range from few GeV up to 50 TeV and to infer the primary CR radial distribution above 100 GeV. We find that the bulk of the Galactic ridge emission can be naturally explained by the interaction of the diffuse, steady-state Galactic CR sea interacting with the gas present in the CMZ. As a consequence, the evidence of a GC Pevatron is significantly weakened.

The very high energy gamma-ray diffuse emission from the galactic center / Gaggero, D.; Grasso, D.; Marinelli, A.; Taoso, M.; Urbano, A.; Ventura, S.. - In: POS PROCEEDINGS OF SCIENCE. - ISSN 1824-8039. - (2017).

The very high energy gamma-ray diffuse emission from the galactic center

Marinelli A.;
2017

Abstract

We present a novel interpretation of the gamma-ray diffuse emission in the Galactic Center (GC) and the Central Molecular Zone (CMZ) regions. This is based on a scenario assuming a harder scaling of the diffusion coefficient with rigidity in the inner Galaxy which reproduces the radial dependence of the cosmic-ray (CR) spectral index recently inferred from Fermi-LAT. We compare our model with H.E.S.S. and (for the fist time in this context) with PASS8 Fermi-LAT data which allows to cover the entire energy range from few GeV up to 50 TeV and to infer the primary CR radial distribution above 100 GeV. We find that the bulk of the Galactic ridge emission can be naturally explained by the interaction of the diffuse, steady-state Galactic CR sea interacting with the gas present in the CMZ. As a consequence, the evidence of a GC Pevatron is significantly weakened.
2017
The very high energy gamma-ray diffuse emission from the galactic center / Gaggero, D.; Grasso, D.; Marinelli, A.; Taoso, M.; Urbano, A.; Ventura, S.. - In: POS PROCEEDINGS OF SCIENCE. - ISSN 1824-8039. - (2017).
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/928225
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