Anomalous anisotropies of cosmic rays from turbulent magnetic fields.

نویسنده

  • Markus Ahlers
چکیده

The propagation of cosmic rays (CRs) in turbulent interstellar magnetic fields is typically described as a spatial diffusion process. This formalism predicts only a small deviation from an isotropic CR distribution in the form of a dipole in the direction of the CR density gradient or relative background flow. We show that the existence of a global CR dipole moment necessarily generates a spectrum of higher multipole moments in the local CR distribution. These anomalous anisotropies are a direct consequence of Liouville's theorem in the presence of a local turbulent magnetic field. We show that the predictions of this model are in excellent agreement with the observed power spectrum of multi-TeV CRs.

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عنوان ژورنال:
  • Physical review letters

دوره 112 2  شماره 

صفحات  -

تاریخ انتشار 2014