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Author Wang, Yang ♦ Qin, Gang
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ ACCELERATION ♦ COMPUTERIZED SIMULATION ♦ DIFFUSION ♦ DISTRIBUTION FUNCTIONS ♦ INTERPLANETARY SPACE ♦ MASS ♦ NUMERICAL SOLUTION ♦ SOLAR PARTICLES ♦ SUN ♦ TRANSPORT THEORY
Abstract The spatial and temporal invariance in the spectra of energetic particles in gradual solar events is reproduced in simulations. Based on a numerical solution of the focused transport equation, we obtain the intensity time profiles of solar energetic particles (SEPs) accelerated by an interplanetary shock in three-dimensional interplanetary space. The shock is treated as a moving source of energetic particles with a distribution function. The time profiles of particle fluxes with different energies are calculated in the ecliptic at 1 AU. According to our model, we find that shock acceleration strength, parallel diffusion, and adiabatic cooling are the main factors in forming the spatial invariance in SEP spectra, and perpendicular diffusion is a secondary factor. In addition, the temporal invariance in SEP spectra is mainly due to the effects of adiabatic cooling. Furthermore, a spectra invariant region, which agrees with observations but is different from the one suggested by Reames et al. is proposed based on our simulations.
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-06-20
Publisher Place United States
Journal Astrophysical Journal
Volume Number 806
Issue Number 2


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