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Related papers: Cosmic-Ray Transport in Varying Galactic Environme…

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Propagation of cosmic rays (CRs) in turbulent and magnetized astrophysical media is a long-standing problem that requires both understanding of the properties of turbulent magnetic fields and their interaction with energetic particles. This…

Astrophysics of Galaxies · Physics 2023-04-07 Alex Lazarian , Siyao Xu , Yue Hu

Motivated by the discovery of the non-thermal Fermi bubble features both below and above the Galactic plane, we investigate a scenario in which these bubbles are formed through Galacto-centric outflow. Cosmic rays (CR) both diffusing and…

High Energy Astrophysical Phenomena · Physics 2017-01-11 Andrew M. Taylor , Gwenael Giacinti

We investigate the impact of cosmic rays (CRs) on the circumgalactic medium (CGM) in FIRE-2 simulations, for ultra-faint dwarf through Milky Way (MW)-mass halos hosting star-forming (SF) galaxies. Our CR treatment includes injection by…

Weakly collisional, magnetised plasmas characterised by anisotropic viscosity and conduction are ubiquitous in galaxies, halos and the intracluster medium (ICM). Cosmic rays (CRs) play an important role in these environments as well, by…

Astrophysics of Galaxies · Physics 2020-03-04 Philipp Kempski , Eliot Quataert , Jonathan Squire

The circumgalactic medium (CGM) plays a critical role in galaxy evolution, influencing gas flows, feedback processes, and galactic dynamics. Observations show a substantial cold gas reservoir in the CGM, but the mechanisms driving its…

Astrophysics of Galaxies · Physics 2025-06-11 Matthias Weber , Timon Thomas , Christoph Pfrommer , Ruediger Pakmor

We discuss new methods to integrate the cosmic ray (CR) evolution equations coupled to magneto-hydrodynamics (MHD) on an unstructured moving mesh, as realised in the massively parallel AREPO code for cosmological simulations. We account for…

Astrophysics of Galaxies · Physics 2017-01-11 C. Pfrommer , R. Pakmor , K. Schaal , C. M. Simpson , V. Springel

We show that the well-known discrepancy between the radial dependence of the Galactic cosmic ray (CR) nucleon distribution, as inferred most recently from EGRET observations of diffuse gamma-rays above 100 MeV, and of the most likely CR…

Astrophysics · Physics 2009-11-07 D. Breitschwerdt , V. A. Dogiel , H. J. Voelk

Cosmic rays (CRs) propagate in the Milky Way and interact with the interstellar medium and magnetic fields. These interactions produce emissions that span the electromagnetic spectrum, and are an invaluable tool for understanding the…

High Energy Astrophysical Phenomena · Physics 2017-12-29 E. Orlando , P. Harrington , A. W. Strong

We study the change in cosmic-ray pressure, the change in cosmic-ray density, and the level of cosmic-ray induced heating via Alfven-wave damping when cosmic rays move from a hot ionized plasma to a cool cloud embedded in that plasma. The…

Astrophysics of Galaxies · Physics 2015-05-28 John E. Everett , Ellen G. Zweibel

Galactic cosmic rays (CR) are particles presumably accelerated in supernova remnant shocks that propagate in the interstellar medium up to the densest parts of molecular clouds, losing energy and their ionisation efficiency because of the…

High Energy Astrophysical Phenomena · Physics 2016-05-25 M. Padovani , A. Marcowith , P. Hennebelle , K. Ferrière

Galactic-scale winds are a generic feature of massive galaxies with high star formation rates across a broad range of redshifts. Despite their importance, a detailed physical understanding of what drives these mass-loaded global flows has…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Munier Salem , Greg L. Bryan

We introduce a novel diffusion model for the propagation of cosmic rays (CRs) that incorporates an anisotropic diffusion tensor of a general form within a realistically modeled large-scale Galactic magnetic field. The parameters of the…

High Energy Astrophysical Phenomena · Physics 2025-07-22 V. D. Borisov , V. O. Yurovsky , I. A. Kudryashov

We model the transport and spectral evolution of 1-100 GeV cosmic ray (CR) electrons (CREs) in TIGRESS MHD simulations of the magnetized, multiphase interstellar medium. We post-process a kpc-sized galactic disk patch representative of the…

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

We analyse the transport of cosmic rays (CR) in magnetic fields that are structured on scales greater than the CR Larmor radius. We solve the Vlasov-Fokker-Planck (VFP) equation for various mixes of mirroring and small-angle scattering and…

High Energy Astrophysical Phenomena · Physics 2025-04-09 A. R. Bell , J. H. Matthews , A. M. Taylor , G. Giacinti

The transport of charged particles in disorganised magnetic fields is an important issue which concerns the propagation of cosmic rays of all energies in a variety of astrophysical environments, such as the interplanetary, interstellar and…

Astrophysics · Physics 2009-11-07 Fabien Casse , Martin Lemoine , Guy Pelletier

Current-day cosmic ray (CR) propagation studies use static Milky-Way models and fit parametrized source distributions to data. Instead, we use three-dimensional magneto-hydrodynamical (MHD) simulations of isolated galaxies with the…

High Energy Astrophysical Phenomena · Physics 2021-05-25 Maria Werhahn , Christoph Pfrommer , Philipp Girichidis , Ewald Puchwein , Rüdiger Pakmor

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

Analyses of TeV-PeV cosmic ray (CR) diffusion around their sources usually assume either isotropic diffusion or anisotropic diffusion due to the regular Galactic magnetic field. We show that none of them are adequate on distances smaller…

High Energy Astrophysical Phenomena · Physics 2013-07-29 G. Giacinti , M. Kachelriess , D. V. Semikoz

Cosmic rays (CRs) are transported out of the galaxy by diffusion and advection due to streaming along magnetic field lines and resonant scattering off self-excited Magneto-Hydro-Dynamic (MHD) waves. Thus momentum is transferred to the…

Astrophysics of Galaxies · Physics 2019-10-02 E. A. Dorfi , D. Steiner , F. Ragossnig , D. Breitschwerdt

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