publication . Article . Other literature type . Preprint . 2015

Gamma-ray sky points to radial gradients in cosmic-ray transport

Gaggero, Daniele; Urbano, Alfredo; Valli, Mauro; Ullio, Piero;
Open Access English
  • Published: 28 Apr 2015
Abstract
The standard approach to cosmic-ray (CR) propagation in the Galaxy is based on the assumption that local transport properties can be extrapolated to the whole CR confining volume. Such models tend to underestimate the gamma-ray flux above few GeV measured by the Fermi Large Area Telescope towards the inner Galactic plane. We consider here for the first time a phenomenological scenario allowing for both the rigidity scaling of the diffusion coefficient and convective effects to be position-dependent. We show that within this approach we can reproduce the observed gamma-ray spectra at both low and mid Galactic latitudes - including the Galactic center - without sp...
Subjects
arXiv: Astrophysics::High Energy Astrophysical PhenomenaAstrophysics::Galaxy AstrophysicsAstrophysics::Cosmology and Extragalactic Astrophysics
free text keywords: Nuclear and High Energy Physics, interstellar-medium; magnetic-field; fermi bubbles; propagation; emission; nuclei; galaxy; constraints; spectra; plane, Settore FIS/02 - Fisica Teorica, Modelli e Metodi Matematici, Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Phenomenology, Gamma ray, Physics, Galaxy, Cosmic ray, Galactic Center, Fermi Gamma-ray Space Telescope, Astrophysics, Galactic plane, Flux, Gamma-ray burst
Funded by
EC| DAMESYFLA
Project
DAMESYFLA
Electroweak Symmetry Breaking, Flavor and Dark Matter: One Solution for Three Mysteries
  • Funder: European Commission (EC)
  • Project Code: 267985
  • Funding stream: FP7 | SP2 | ERC
,
EC| INVISIBLES
Project
INVISIBLES
INVISIBLES
  • Funder: European Commission (EC)
  • Project Code: 289442
  • Funding stream: FP7 | SP3 | PEOPLE
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