Cosmic ray transport near the heliopause

14th Annual International Astrophysics Conference: Linear and Nonlinear Particle Energization throughout the Heliosphere and Beyond

物理学;天文学

Strauss, R.D.^1,2 ; Fichtner, H.^3 ; Potgieter, M.S.^1 ; Le Roux, J.A.^2 ; Luo, X.^1,4

Center for Space Research, North-West University, South Africa^1

Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, United States^2

Institut für Theoretische Physik IV, Ruhr Universität, Bochum, Germany^3

National Space Science Center CAS, Beijing, China^4

关键词: Anisotropic behaviours;    Cosmic ray intensity;    Galactic and anomalous cosmic rays;    Galactic cosmic ray modulations;    Local interstellar medium;    Modulation effects;    Perpendicular diffusion;    Tangential discontinuities;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/642/1/012026/pdf
DOI  :  10.1088/1742-6596/642/1/012026

学科分类：天文学(综合)

来源: IOP

【 摘 要 】

In this paper we summarize our modelling efforts for cosmic rays near the heliopause, and discuss whether galactic cosmic ray modulation beyond the heliopause is possible and present an explanation for the anisotropic nature of the observed cosmic ray intensities in the very local interstellar medium. We show that (i) modulation beyond the heliopause is possible, but highly dependent on the assumed parameters (most notable, the perpendicular diffusion coefficient). Treating the heliopause as a tangential discontinuity, significantly damps this modulation effect and leads to modelled results that are similar to Voyager 1 observations. (ii) By choosing an appropriate functional form of the perpendicular diffusion coefficient on the pitch-angle level, we are able to account for the anisotropic behaviour observed for both galactic and anomalous cosmic rays in the local interstellar medium.