THE INFLUENCE OF KLEIN-NISHINA STEPS ON THE SPATIAL DIFFUSION OF GALACTIC COSMIC-RAY ELECTRONS

Journal Article · Sun May 20 00:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/751/1/71· OSTI ID:22037216

Blies, P; Schlickeiser, R ^[1]

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1. Institut fuer Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)

The full Klein-Nishina cross section for the inverse Compton scattering interactions of electrons implies a significant reduction of the electron energy loss rate compared to the Thomson limit when the electron energy exceeds the critical Klein-Nishina energy E{sub K} = 0.27m{sup 2}{sub e} c{sup 4}/(k{sub B}T), where T denotes the temperature of the photon graybody distribution. We investigate the influence of the Klein-Nishina reduction on the solution of the steady-state spatial diffusion transport equation for relativistic electrons. The modified electron spectrum at energies below 10{sup 4} GeV, where only the Klein-Nishina modifications from interstellar optical target photons are relevant, are derived in terms of the Green's function solution for one-, two-, and three-dimensional spatial diffusion. The modifications to the solutions of the one- and three-dimensional diffusion equations are calculated for a single point source of monoenergetic electrons. It is shown that significant enhancements in the local electron intensity occur at electron energies greater than the critical Klein-Nishina energy E{sub K} , and that the cosmic-ray electron anisotropy at the solar system resulting from a single steady point source exhibits a sharp drop near E{sub K} . These Klein-Nishina enhancements are potentially interesting for determining the contribution of point sources such as dark matter sources and/or electromagnetic particle accelerators (pulsars and micro-quasars) to the local electron intensity and the local positron fraction.

• OSTI ID: 22037216
• Journal Information: Astrophysical Journal, Vol. 751, 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
COMPTON EFFECT
COSMIC ELECTRONS
COSMIC PHOTONS
COSMIC POSITRONS
CROSS SECTIONS
DIFFUSION
DIFFUSION EQUATIONS
ELECTRON SPECTRA
ENERGY LOSSES
GEV RANGE
GREEN FUNCTION
KLEIN-NISHINA FORMULA
NONLUMINOUS MATTER
POINT SOURCES
PULSARS
QUASARS
RELATIVISTIC RANGE
THREE-DIMENSIONAL CALCULATIONS
TRANSPORT THEORY