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We calculate the diffusion coefficients of charged cosmic rays (CR) propagating in regular and turbulent magnetic fields. If the magnetic field is dominated by an isotropic turbulent component, we find that CRs reside too long in the…

High Energy Astrophysical Phenomena · Physics 2018-07-24 G. Giacinti , M. Kachelriess , D. V. Semikoz

We review numerical methods for simulations of cosmic ray (CR) propagation on galactic and larger scales. We present the development of algorithms designed for phenomenological and self-consistent models of CR propagation in kinetic…

High Energy Astrophysical Phenomena · Physics 2021-06-17 M. Hanasz , A. Strong , P. Girichidis

The paper numerically investigates the propagation of galactic cosmic rays in a model magnetic field, which is a composition of an isotropic turbulent field with the Kolmogorov turbulence spectrum and a regular constant field. The…

High Energy Astrophysical Phenomena · Physics 2024-11-08 V. O Yurovsky , A. I. Peryatinskaya , I. Kudryashov

In the standard picture of cosmic ray transport the propagation of charged cosmic rays through turbulent magnetic fields is described as a random walk with cosmic rays scattering on magnetic field turbulence. This is in good agreement with…

High Energy Astrophysical Phenomena · Physics 2021-07-08 Marco Kuhlen , Philipp Mertsch , Vo Hong Minh Phan

Nowadays, the calculation of the Galactic Cosmic Rays diffusion coefficient with direct microscopic numerical simulations is a widespread approach. In this work, we investigated the numerical limits for such calculations and demonstrated…

Instrumentation and Methods for Astrophysics · Physics 2026-05-14 Vladimir Yurovsky , Ilya Kudryashov

Multichannel Cosmic Ray (CR) spectra and the large scale CR anisotropy can hardly be made compatible in the framework of conventional isotropic and homogeneous propagation models. These models also have problems explaining the longitude…

High Energy Astrophysical Phenomena · Physics 2012-06-13 Carmelo Evoli , Daniele Gaggero , Dario Grasso , Luca Maccione

We present the results of a numerical simulation of propagation of cosmic rays with energy above $10^{15}$ eV in a complex magnetic field, made in general of a large scale component and a turbulent component. Several configurations are…

Astrophysics · Physics 2009-11-13 Daniel De Marco , Pasquale Blasi , Todor Stanev

A correct description of cosmic-ray (CR) diffusion in turbulent plasma is essential for many astrophysical and heliospheric problems. This paper aims to present physical diffusion behavior of CRs in actual turbulent magnetic fields, model…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Siyao Xu , Huirong Yan

Isotropic diffusion models for Galactic cosmic ray transport put tight constraints on the maximum convection velocity in the halo. For a half halo height of 4 kpc the maximum convection speed is limited to 40 km/s in the halo, since…

Astrophysics of Galaxies · Physics 2009-10-13 Iris Gebauer , Wim de Boer

The development of an analytically iterative method for solving steady-state as well as unsteady-state problems of cosmic-ray (CR) modulation is proposed. Iterations for obtaining the solutions are constructed for the spherically symmetric…

Instrumentation and Methods for Astrophysics · Physics 2017-07-04 Yuriy L. Kolesnyk , Pavol Bobik , Boris A. Shakhov , Marian Putis

Under nonuniform convection, the distribution of diffusive particles can exhibit dipole and quadrupole anisotropy induced by the fluid inertial and shear force, respectively. These convection-related anisotropies, unlike the Compton-Getting…

High Energy Astrophysical Phenomena · Physics 2022-10-26 Yiran Zhang , Siming Liu , Dejin Wu

An extensive program for the calculation of galactic cosmic-ray propagation has been developed. Primary and secondary nucleons, primary and secondary electrons, and secondary positrons are included. The basic spatial propagation mechanisms…

Astrophysics · Physics 2008-02-03 A. W. Strong , I. V. Moskalenko , V. Schoenfelder

The growth of magneto-hydrodynamic fluctuations relevant to cosmic ray confinement in and near their sources, and the effects of local plasma conditions is revisited. We consider cases where cosmic rays penetrate a medium which may contain…

High Energy Astrophysical Phenomena · Physics 2021-02-10 B. Reville , G. Giacinti , R. Scott

We obtain the dipolar anisotropies in the arrival directions of ultra-high energy cosmic rays diffusing from nearby extragalactic sources. We discuss both the energy regime of spatial diffusion and the quasi-rectilinear one leading to just…

High Energy Astrophysical Phenomena · Physics 2014-06-11 Diego Harari , Silvia Mollerach , Esteban Roulet

We study the nonlinear growth of kinetic gyroresonance instability of cosmic rays (CRs) induced by large scale compressible turbulence. This feedback of cosmic rays on turbulence was shown to induce an important scattering mechanism in…

High Energy Astrophysical Phenomena · Physics 2011-03-28 Huirong Yan , A. Lazarian

The propagation of charged cosmic rays through the Galactic environment influences all aspects of the observation at Earth. Energy spectrum, composition and arrival directions are changed due to deflections in magnetic fields and…

Instrumentation and Methods for Astrophysics · Physics 2017-07-26 Lukas Merten , Julia Becker Tjus , Horst Fichtner , Björn Eichmann , Günter Sigl

We solve the anisotropic diffusion equation in 2D, where the dominant direction of diffusion is defined by a vector field which does not conform to a Cartesian grid. Our method uses operator splitting to separate the diffusion perpendicular…

Numerical Analysis · Mathematics 2023-03-29 Dean Muir , Kenneth Duru , Matthew Hole , Stuart Hudson

We present version 2 of the DRAGON code designed for computing realistic predictions of the CR densities in the Galaxy. The code numerically solves the interstellar CR transport equation (including inhomogeneous and anisotropic diffusion,…

High Energy Astrophysical Phenomena · Physics 2017-03-28 Carmelo Evoli , Daniele Gaggero , Andrea Vittino , Giuseppe Di Bernardo , Mattia Di Mauro , Arianna Ligorini , Piero Ullio , Dario Grasso

Energetic particle transport in a finite amplitude magnetosonic and Alfvenic turbulence is considered using Monte Carlo particle simulations, which involve an integration of particle equation of motion. We show that in a low-Betha plasma…

Astrophysics · Physics 2008-02-03 G. Michalek , M. Ostrowski , R. Schlickeiser

We consider anisotropic diffusion of Galactic cosmic rays in the Galactic magnetic field, using the Jansson-Farrar model for the field. In this paper we investigate the influence of source position on the cosmic ray flux at Earth in two…

Astrophysics of Galaxies · Physics 2020-01-29 A. AL-Zetoun , A. Achterberg