1 research outputs found
Cosmic-Ray Nuclei, Antiprotons and Gamma-rays in the Galaxy: a New Diffusion Model
We model the transport of cosmic ray nuclei in the Galaxy by means of a new
numerical code. Differently from previous numerical models we account for a
generic spatial distribution of the diffusion coefficient. We found that in the
case of radially uniform diffusion, the main secondary/primary ratios (B/C, N/O
and sub-Fe/Fe) and the modulated antiproton spectrum match consistently the
available observations. Convection and re-acceleration do not seem to be
required in the energy range we consider: GeV/nucleon. We
generalize these results accounting for radial dependence of the diffusion
coefficient, which is assumed to trace that of the cosmic ray sources. While
this does not affect the prediction of secondary/primary ratios, the simulated
longitude profile of the diffuse -ray emission is significantly
different from the uniform case and may agree with EGRET measurements without
invoking ad hoc assumptions on the galactic gas density distribution.Comment: 17 pages, 6 figures. v3: Added detailed references to nuclear
cross-section networ