Diffuse Galactic continuum gamma rays
arXiv:astro-ph/9912102 · doi:10.1063/1.1303219
Abstract
Galactic diffuse continuum gamma-ray emission is intricately related to cosmic-ray physics and radio astronomy. We describe recent results from an approach which endeavours to take advantage of this. Information from cosmic-ray composition constrains the propagation of cosmic rays; this in turn can be used as input for gamma-ray models. The GeV gamma-ray excess cannot be explained as neutral pion decay resulting from a hard nucleon spectrum without violating antiproton and positron data; the best explanation at present appears to be inverse-Compton emission from a hard interstellar electron spectrum. One consequence is an increased importance of Galactic inverse Compton for estimates of the extragalactic background. At low energies, an additional point-source component of gamma-rays seems to be necessary.
arXiv comment8 pages, 15 ps-figures; invited talk, to appear in Proc. 5th Compton Symp. (Portsmouth, NH, Sep. 1999), AIP, in press. More details can be found at http://www.gamma.mpe-garching.mpg.de/~aws/aws.html