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Title: SMALL-SCALE ANISOTROPIES OF COSMIC RAYS FROM RELATIVE DIFFUSION

The arrival directions of multi-TeV cosmic rays show significant anisotropies at small angular scales. It has been argued that this small-scale structure can naturally arise from cosmic ray scattering in local turbulent magnetic fields that distort a global dipole anisotropy set by diffusion. We study this effect in terms of the power spectrum of cosmic ray arrival directions and show that the strength of small-scale anisotropies is related to properties of relative diffusion. We provide a formalism for how these power spectra can be inferred from simulations and motivate a simple analytic extension of the ensemble-averaged diffusion equation that can account for the effect.
Authors:
 [1] ;  [2]
  1. WIPAC and Department of Physics, University of Wisconsin–Madison, Madison, WI 53706 (United States)
  2. Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, CA 94025 (United States)
Publication Date:
OSTI Identifier:
22518665
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 815; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANISOTROPY; COSMIC RADIATION; DIFFUSION; DIFFUSION EQUATIONS; DIPOLES; ENERGY SPECTRA; MAGNETIC FIELDS; SCATTERING; TEV RANGE; TURBULENCE