ANISOTROPY OF TeV COSMIC RAYS AND OUTER HELIOSPHERIC BOUNDARIES

Journal Article · Tue Jan 01 00:00:00 EST 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/762/1/44· OSTI ID:22167313

Desiati, P. ^[1]; Lazarian, A. ^[2]

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1. Wisconsin IceCube Particle Astrophysics Center (WIPAC), Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States)
2. Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States)

Cosmic rays in the energy range from about tens of GeV to several hundreds of TeV are observed on Earth, with an energy-dependent anisotropy of order 0.01%-0.1% and a consistent topology that appears to significantly change at higher energy. The nearest and most recent galactic cosmic-ray sources might stochastically dominate the observation and possibly explain a change in orientation of the anisotropy as a function of energy. However, the diffusion approximation is not able to explain its non-dipolar structure and, in particular, the significant contribution of small angular scale features. Particle propagation within the mean free path in the local interstellar medium might have a major role in determining the properties of galactic cosmic rays, such as their arrival distribution. In particular, scattering on perturbations induced in the local interstellar magnetic field by the heliosphere wake may cause a re-distribution of anisotropic cosmic rays below about 100 TeV toward the direction of the elongated heliotail and of the local interstellar magnetic field in the outer heliosphere. Such scattering processes are considered responsible for the observed TeV cosmic-ray global anisotropy and its fine angular structure.

• OSTI ID: 22167313
• Journal Information: Astrophysical Journal, Vol. 762, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ANISOTROPY
APPROXIMATIONS
ASTRONOMY
ASTROPHYSICS
COSMIC RAY PROPAGATION
COSMIC RAY SOURCES
DIFFUSION
DISTURBANCES
ENERGY DEPENDENCE
GEV RANGE
HELIOSPHERE
INTERSTELLAR MAGNETIC FIELDS
MEAN FREE PATH
ORIENTATION
PRIMARY COSMIC RADIATION
SCATTERING
STOCHASTIC PROCESSES
SUN
TEV RANGE
TURBULENCE