Friday, June 14, 2013

1306.3209 (G. Giacinti et al.)

Anisotropic Cosmic Ray Diffusion and its Implications for Gamma Ray Astronomy    [PDF]

G. Giacinti, M. Kachelriess, D. V. Semikoz
Analyses of TeV-PeV cosmic ray (CR) diffusion around their sources usually assume either isotropic diffusion or anisotropic diffusion due to the regular Galactic magnetic field. We show that none of them is adequate on distances smaller than the maximal scale Lmax ~ 100 pc of fluctuations in the turbulent interstellar magnetic field. As a result, we predict anisotropic gamma-ray emissions around CR proton and electron sources, even for uniform densities of target gas. The centers of extended emission regions may have non-negligible offsets from their sources, leading to the risk of misidentifications. Gamma-rays from CR filaments have steeper energy spectra than those from surrounding regions. We point out that gamma-ray telescopes can be used in the future as a new way to probe and to deduce the parameters of the interstellar magnetic field.
View original: http://arxiv.org/abs/1306.3209

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