1111.2536 (G. Giacinti et al.)
G. Giacinti, G. Sigl
In the energy range from ~ 10^12 eV to ~ 10^15 eV, the Galactic cosmic ray
flux has anisotropies both on large scales, with an amplitude of the order of
0.1%, and on scales between ~ 10 and ~ 30 degrees, with amplitudes smaller by a
factor of a few. With a diffusion coefficient inferred from Galactic cosmic ray
chemical abundances, the diffusion approximation predicts a dipolar anisotropy
of comparable size, but does not explain the smaller scale anisotropies. We
demonstrate here that energy dependent smaller scale anisotropies naturally
arise from the local concrete realization of the turbulent magnetic field
within the cosmic ray scattering length. We show how such anisotropies could be
calculated if the magnetic field structure within a few tens of parsecs from
Earth would be known.
View original:
http://arxiv.org/abs/1111.2536
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