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Related papers: A New Numerical Scheme for Cosmic Ray Transport

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Cosmic rays (CRs) have recently re-emerged as attractive candidates for mediating feedback in galaxies because of their long cooling timescales. They can have energy densities comparable to the thermal gas, but do not suffer catastrophic…

Astrophysics of Galaxies · Physics 2017-01-25 Joshua Wiener , Christoph Pfrommer , S. Peng Oh

The gyro-resonant cosmic-ray (CR) streaming instability is believed to play a crucial role in CR transport, leading to growth of Alfv\'en waves at small scales that scatter CRs, and impacts the interaction of CRs with the ISM on large…

High Energy Astrophysical Phenomena · Physics 2019-05-15 Xue-Ning Bai , Eve C. Ostriker , Illya Plotnikov , James M. Stone

Numerical modeling of galactic cosmic rays (GCRs) penetration through the heliosphere to the vicinity of the Sun is considered. Galactic cosmic rays are charged particles with energies exceeding 10 MeV/nucl., originating from far beyond the…

High Energy Astrophysical Phenomena · Physics 2025-09-04 D. A. Shestakov , V. V. Izmodenov

Cosmic ray (CR) transport and acceleration is determined by the properties of magnetic turbulence. Recent advances in MHD turbulence call for revisions in the paradigm of cosmic ray transport. We use the models of magnetohydrodynamic…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Huirong Yan

We present a novel implementation of cosmic rays (CR) in the magneto-hydrodynamic code FLASH. CRs are described as separate fluids with different energies. CR advection, energy dependent anisotropic diffusion with respect to the magnetic…

High Energy Astrophysical Phenomena · Physics 2014-06-20 Philipp Girichidis , Thorsten Naab , Stefanie Walch , Michal Hanasz

Recent advances on gamma-ray observations from SuperNova Remnants and Molecular Clouds offer the possibility to study in detail the properties of the propagation of escaping Cosmic Rays (CR). However, a complete theory for CR transport…

High Energy Astrophysical Phenomena · Physics 2015-09-09 Lara Nava , Stefano Gabici , Alexandre Marcowith , Giovanni Morlino , Vladimir Ptuskin

We derive a consistent set of moments equations for CR-magnetohydrodynamics, assuming a gyrotropic distribution function (DF). Unlike previous efforts we derive a closure, akin to the M1 closure in radiation hydrodynamics (RHD), that is…

High Energy Astrophysical Phenomena · Physics 2022-03-18 Philip F. Hopkins , Jonathan Squire , Iryna S. Butsky

Using hybrid simulations (kinetic ions--fluid electrons), we test the linear theory predictions of the cosmic ray (CR) streaming instability. We consider two types of CR distribution functions: a "hot" distribution where CRs are represented…

High Energy Astrophysical Phenomena · Physics 2019-09-16 Colby Haggerty , Damiano Caprioli , Ellen Zweibel

When a magnetised, thermal plasma containing a shock wave efficiently accelerates Cosmic Rays (CR) a reaction is exerted on the fluid structure. The simplest description of this process involves three conservation equations for the…

Astrophysics · Physics 2007-05-23 P. Duffy , L. O'C. Drury , H. J. Voelk

Cosmic ray transport on galactic scales depends on the detailed properties of the magnetized, multiphase interstellar medium (ISM). In this work, we post-process a high-resolution TIGRESS magnetohydrodynamic simulation modeling a local…

High Energy Astrophysical Phenomena · Physics 2021-11-24 Lucia Armillotta , Eve C. Ostriker , Yan-Fei Jiang

Fluid approximations to cosmic ray (CR) transport are often preferred to kinetic descriptions in studies of the dynamics of the interstellar medium (ISM) of galaxies, because they allow simpler analytical and numerical treatments.…

High Energy Astrophysical Phenomena · Physics 2019-06-04 L. F. S. Rodrigues , A. P. Snodin , G. R. Sarson , Anvar Shukurov

We investigate the transport of spectrally resolved cosmic ray (CR) protons with kinetic energies between $1-100$ GeV within the dynamic, multiphase interstellar medium (ISM), using a two-moment CR fluid solver applied to a TIGRESS MHD…

High Energy Astrophysical Phenomena · Physics 2025-07-02 Lucia Armillotta , Eve C. Ostriker , Nora B. Linzer

The equation governing the streaming of a quantity down its gradient superficially looks similar to the simple constant velocity advection equation. In fact, it is the same as an advection equation if there are no local extrema in the…

High Energy Astrophysical Phenomena · Physics 2015-03-13 Prateek Sharma , Phillip Colella , Daniel F. Martin

This paper presents a new resolution strategy for multi-scale streamer discharge simulations based on a second order time adaptive integration and space adaptive multiresolution. A classical fluid model is used to describe plasma…

Numerical Analysis · Mathematics 2012-04-10 Max Duarte , Zdenek Bonaventura , Marc Massot , Anne Bourdon , Stéphane Descombes , Thierry Dumont

Cosmic rays (CRs) have critical impacts in the multiphase interstellar medium (ISM), driving dynamical motions in low-density plasma and modifying the ionization state, temperature, and chemical composition of higher-density atomic and…

Astrophysics of Galaxies · Physics 2022-02-23 Christopher J. Bambic , Xue-Ning Bai , Eve C. Ostriker

The majority of galactic baryons reside outside of the galactic disk in the diffuse gas known as the circumgalactic medium (CGM). While state-of-the art simulations excel at reproducing galactic disk properties, many struggle to drive…

Astrophysics of Galaxies · Physics 2018-12-05 Iryna Butsky , Thomas R. Quinn

A cosmological hydrodynamic code is described, which includes a routine to compute cosmic ray acceleration and transport in a simplified way. The routine was designed to follow explicitly diffusive acceleration at shocks, and second-order…

Astrophysics · Physics 2007-05-23 Dongsu Ryu , Francesco Miniati , Tom W. Jones , Hyesung Kang

A crucial process in Galactic cosmic-ray (CR) transport is the spatial diffusion due to the interaction with the interstellar turbulent magnetic field. Usually, CR diffusion is assumed to be uniform and isotropic all across the Galaxy.…

High Energy Astrophysical Phenomena · Physics 2017-10-25 Silvio Sergio Cerri , Daniele Gaggero , Andrea Vittino , Carmelo Evoli , Dario Grasso

Cosmic rays (CRs) are an integral part of the non-thermal pressure budget in the interstellar medium (ISM) and are the leading-order ionization mechanism in cold molecular clouds. We study the impacts that different microphysical CR…

Recently, cosmic ray (CR) feedback has been identified as a critical process in galaxy formation but most previous simulations have integrated out the energy-dependence of the CR distribution, despite its large extent over more than twelve…

Astrophysics of Galaxies · Physics 2023-03-15 Philipp Girichidis , Christoph Pfrommer , Rüdiger Pakmor , Volker Springel