English

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

High Energy Astrophysical Phenomena 2016-06-22 v1

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.

Keywords

Cite

@article{arxiv.1507.07796,
  title  = {Gamma-ray and neutrino diffuse emissions of the Galaxy above the TeV},
  author = {Daniele Gaggero and Dario Grasso and Antonio Marinelli and Alfredo Urbano and Mauro Valli},
  journal= {arXiv preprint arXiv:1507.07796},
  year   = {2016}
}

Comments

Oral contribution to the 34th International Cosmic Ray Conference, July 30 to August 6, The Hague, Netherlands