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arXiv · 1507.07796

Gamma-ray and neutrino diffuse emissions of the Galaxy above the TeV

Daniele Gaggero·Dario Grasso·Antonio Marinelli·Alfredo Urbano·Mauro Valli
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Abstract

As recently shown, Fermi-LAT measurements of the diffuse gamma-ray emission from the Galaxy favor the presence of a smooth softening in the primary cosmic-ray spectrum with increasing Galactocentric distance. This result can be interpreted in terms of a spatial-dependent rigidity scaling of the diffusion coefficient. The DRAGON code was used to build a model based on such feature. That scenario correctly reproduces the latest Fermi-LAT results as well as local cosmic-ray measurements from PAMELA, AMS-02 and CREAM. Here we show that the model, if extrapolated at larger energies, grasps both the gamma-ray flux measured by MILAGRO at 15 TeV and the H.E.S.S. data from the Galactic ridge, assuming that the cosmic-ray spectral hardening found by those experiments at about 250 GeV/n is present in the whole inner Galactic plane region. Moreover, we show as that model also predicts a neutrino emission which may account for a significant fraction, as well as for the correct spectral shape, of the astrophysical flux measured by IceCube above 25 TeV.

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Daniele Gaggero, Dario Grasso, Antonio Marinelli, Alfredo Urbano, Mauro Valli. 2015-07-28. Gamma-ray and neutrino diffuse emissions of the Galaxy above the TeV. https://doi.org/10.1088/1742-6596/718/5/052018

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