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Related papers: Diffusive Versus Free-Streaming Cosmic Ray Transpo…

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The tension between recent observations and theories on cosmic ray (CR) diffusion necessitates exploration of new CR diffusion mechanisms. We perform the first numerical study on the mirror diffusion of CRs that is recently proposed by…

High Energy Astrophysical Phenomena · Physics 2023-12-01 Chao Zhang , Siyao Xu

We calculate cosmic ray transport with a collisional Boltzmann Transport Equation, including E-M forces. We apply the Crank-Nicholson Method to solve this equation. At each time step, the spatial distribution of cosmic rays is applied to…

High Energy Astrophysical Phenomena · Physics 2011-10-17 Paul Rimmer , Eric Herbst

Cosmic rays (CRs) are ubiquitous in the interstellar medium (ISM) of nearby galaxies, but many of their properties are not well-constrained. Gamma-ray observations provide a powerful tool in this respect, allowing us to constrain both the…

High Energy Astrophysical Phenomena · Physics 2023-07-19 Maria Werhahn , Philipp Girichidis , Christoph Pfrommer , Joseph Whittingham

Cosmic rays (CRs) play a major role in the dynamics of the interstellar medium (ISM). Their interactions and transport ionize, heat, and push the ISM thereby coupling different regions of it. The spatial distribution of CRs depends on the…

The energy spectrum of electrons produced in molecular gas by interstellar cosmic rays (CRs) is rigorously calculated as a function of gas column density $N$ traversed by the CRs. This allows us to accurately compute the local value of the…

Astrophysics of Galaxies · Physics 2021-03-17 Alexei V. Ivlev , Kedron Silsbee , Marco Padovani , Daniele Galli

Diffuse gamma-ray emission from interstellar clouds results largely from cosmic ray (CR) proton collisions with ambient gas, regardless of the gas state, temperature, or dust properties of the cloud. The interstellar medium is predominantly…

High Energy Astrophysical Phenomena · Physics 2017-01-11 Ryan D. Abrahams , Alex Teachey , Timothy A. D. Paglione

The propagation of cosmic rays in turbulent magnetic fields is a diffusive process driven by the scattering of the charged particles by random magnetic fluctuations. Such fields are usually highly intermittent, consisting of intense…

High Energy Astrophysical Phenomena · Physics 2017-04-19 Anvar Shukurov , Andrew Snodin , Amit Seta , Paul Bushby , Toby Wood

The standard approach to cosmic-ray (CR) propagation in the Galaxy is based on the assumption that local transport properties can be extrapolated to the whole CR confining volume. Such models tend to underestimate the gamma-ray flux above…

High Energy Astrophysical Phenomena · Physics 2015-05-06 Daniele Gaggero , Alfredo Urbano , Mauro Valli , Piero Ullio

Various studies firmly establish the fact that gamma-ray observations can act as a unique probe to detect the possible cosmic ray (CR) sources, study the CR density distribution and explore the average properties of interstellar medium…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Sayan Biswas , Nayantara Gupta

Propagation of cosmic rays (CRs) from their sources to the observer is described mainly as plain diffusion at high energies, while at lower energies there are other physical processes involved, both in the interstellar space and in the…

High Energy Astrophysical Phenomena · Physics 2017-01-11 S. Della Torre , M. Gervasi , D. Grandi , G. Johannesson , G. La Vacca , N. Masi , I. V. Moskalenko , E. Orlando , T. A. Porter , L. Quadrani , P. G. Rancoita , D. Rozza

We study the high latitude (|b|>10) diffuse gamma-ray emission in the Galaxy in light of the recently published data from the Fermi collaboration at energies between 100 MeV and 100 GeV. The unprecedented accuracy in these measurements…

High Energy Astrophysical Phenomena · Physics 2013-04-16 I. Cholis , M. Tavakoli , C. Evoli , L. Maccione , P. Ullio

The nature of cosmic rays (CRs) and cosmic ray transport in galaxy clusters is probed by a number of observations. Radio observations reveal the synchrotron radiation of cosmic ray electrons (CRe) spiraling around cluster magnetic fields.…

High Energy Astrophysical Phenomena · Physics 2019-06-26 Joshua Wiener , Ellen G. Zweibel

Cosmic ray propagation is diffusive because of pitch angle scattering by waves. We demonstrate that if the high-amplitude magnetohydrodynamic turbulence with $\tilde B/\langle B\rangle \sim 1$ is present on top of the mean field gradient,…

High Energy Astrophysical Phenomena · Physics 2015-09-30 Mikhail V. Medvedev , Viktor V. Medvedev

Measurements of ultra heavy nuclei at GeV/n energies in the galactic cosmic radiation address the question of the sources (nucleosynthetic s- and r-processes). As such, the determination of CR source abundances is a promising way to…

Astrophysics · Physics 2007-05-23 C. Combet , D. Maurin , J. Donnelly , L. O'C Drury , E. Vangioni-Flam

We construct a model for cosmic ray acceleration from protostellar accretion shocks and calculate the resulting cosmic ray ionization rate within star-forming molecular clouds. We couple a protostar cluster model with an analytic accretion…

Astrophysics of Galaxies · Physics 2018-07-25 Brandt A. L. Gaches , Stella S. R. Offner

Cosmic rays (CRs) are a plausible mechanism for launching winds of cool material from the discs of star-forming galaxies. However, there is no consensus on what types of galaxies likely host CR-driven winds, or what role these winds might…

Astrophysics of Galaxies · Physics 2021-03-03 Roland M. Crocker , Mark R. Krumholz , Todd A. Thompson

We take advantage of the cosmic-ray (CR) proton data collected by the PAMELA detector in several campaigns covering the period 2006-2009 to derive the local interstellar CR proton spectrum (LIS), outside the solar system. We describe the…

High Energy Astrophysical Phenomena · Physics 2013-06-07 Francesco Loparco , Luca Maccione , Mario Nicola Mazziotta

Ever since the discovery of Cosmic Rays (CRs), significant advancements have been made in modeling their propagation in the Galaxy and in the Heliosphere. However, propagation models suffer from degeneracy of many parameters. To complicate…

High Energy Astrophysical Phenomena · Physics 2018-04-19 E. Orlando

The propagation of cosmic rays (CRs) in turbulent interstellar magnetic fields is typically described as a spatial diffusion process. This formalism predicts only a small deviation from an isotropic CR distribution in the form of a dipole…

High Energy Astrophysical Phenomena · Physics 2014-01-22 Markus Ahlers

The diffusion of galactic cosmic rays (CR) is considered. It is anticipated that the nonlinear MHD cascade sets the power-law spectrum of turbulence from the principle scale 100 pc to much smaller scales. We found that the dissipation of…

Astrophysics · Physics 2007-05-23 V. S. Ptuskin , F. C. Jones , I. V. Moskalenko , V. N. Zirakashvili