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Related papers: Stability of Cosmic Ray Modified Shocks: Two-Fluid…

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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 have developed a new, very efficient numerical scheme to solve the CR diffusion convection equation that can be applied to the study of the nonlinear time evolution of CR modified shocks for arbitrary spatial diffusion properties. The…

Astrophysics · Physics 2009-11-11 T. W. Jones , H. Kang

We have developed a cosmic ray (CR) shock code in one dimensional spherical geometry with which the particle distribution, the gas flow and their nonlinear interaction can be followed numerically in a frame comoving with an expanding shock.…

Astrophysics · Physics 2009-11-11 Hyesung Kang , T. W. Jones

Cosmic rays (CRs) are dynamically important for the formation and evolution of galaxies by regulating star formation and by powering galactic outflows. However, to what extent CRs regulate galaxy formation depends on the coupling strength…

Astrophysics of Galaxies · Physics 2023-12-27 Philipp Girichidis , Maria Werhahn , Christoph Pfrommer , Rüdiger Pakmor , Volker Springel

Diffusive shock acceleration is the prime candidate for efficient acceleration of cosmic rays. Galactic cosmic rays are believed to originate predominantly from this process in supernova remnant shock waves. Confinement of the cosmic rays…

High Energy Astrophysical Phenomena · Physics 2011-10-07 K. M. Schure , A. R. Bell

This paper reports the bistability of curved compression ramp (CCR) flows. It reveals that both separation and attachment states can be stably established even for the same boundary conditions. Firstly, to investigate the effects of initial…

Fluid Dynamics · Physics 2022-02-25 Yan-Chao Hu , Gang Wang , Wen-Feng Zhou , Ming-Zhi Tang , Yan-Guang Yang , Zhi-Gong Tang

We develop a formalism for the identification and accurate estimation of the strength of structure formation shocks during cosmological smoothed particle hydrodynamics simulations. Shocks not only play a decisive role for the thermalization…

Astrophysics · Physics 2009-11-11 Christoph Pfrommer , Volker Springel , Torsten A. Ensslin , Martin Jubelgas

Diffusive shock acceleration is a prominent mechanism for producing energetic particles in space and in astrophysical systems. Such energetic particles have long been predicted to affect the hydrodynamic structure of the shock, in turn…

High Energy Astrophysical Phenomena · Physics 2020-12-16 Damiano Caprioli , Colby C. Haggerty , Pasquale Blasi

This paper investigates the nature of the MHD turbulence excited by the streaming of accelerated cosmic rays in a shock wave precursor. The two recognised regimes (non-resonant and resonant) of the streaming instability are taken into…

Astrophysics · Physics 2009-11-11 Guy Pelletier , Martin Lemoine , Alexandre Marcowith

The nonresonant cosmic ray instability, predicted by Bell (2004), is thought to play an important role in the acceleration and confinement of cosmic rays (CRs) close to supernova remnants. Despite its importance, the exact mechanism…

High Energy Astrophysical Phenomena · Physics 2019-09-17 Georgios Zacharegkas , Damiano Caprioli , Colby Haggerty

Over the past decades, there has been growing observational and theoretical evidence that cosmic-ray-induced instabilities play an important role in both acceleration and transport of cosmic rays (CRs). For instance, the efficient…

High Energy Astrophysical Phenomena · Physics 2025-10-07 Antonio Capanema , Pasquale Blasi , Emanuele Sobacchi

The properties of the Galactic supernova remnant SN 1006 are theoretically reanalysed. Nonlinear kinetic theory is used to determine the acceleration efficiency of cosmic rays (CRs) in the supernova remnant SN 1006. The known range of…

High Energy Astrophysical Phenomena · Physics 2011-03-22 E. G. Berezhko , L. T. Ksenofontov , H. J. Voelk

Cosmic rays (CRs) are thought to play an important role in galaxy evolution. We study their effect when coupled to other important sources of feedback, namely supernovae and stellar radiation, by including CR anisotropic diffusion and…

Astrophysics of Galaxies · Physics 2022-05-27 Marion Farcy , Joakim Rosdahl , Yohan Dubois , Jérémy Blaizot , Sergio Martin-Alvarez

Recent precise measurements of cosmic ray (CR) spectra show that the energy distribution of protons is softer than those of heavier nuclei, and there are spectral hardenings for all nuclear compositions above $\sim$200 GV. Models proposed…

High Energy Astrophysical Phenomena · Physics 2017-08-02 Yiran Zhang , Siming Liu , Qiang Yuan

The acceleration of relativistic particles due to repeated scattering across a shock wave remains the most attractive model for the production of energetic cosmic rays. This process has been analyzed extensively during the past two decades…

Astrophysics · Physics 2009-11-06 Peter A. Becker , Demosthenes Kazanas

Cosmic rays (CRs) play a decisive role within our own Galaxy. They provide partial pressure support against gravity, they trace past energetic events such as supernovae, and they reveal the underlying structure of the baryonic matter…

Astrophysics · Physics 2009-11-11 Torsten A. Ensslin , Christoph Pfrommer , Volker Springel , Martin Jubelgas

According to the most popular model for the origin of cosmic rays (CRs), supernova remnants (SNRs) are the site where CRs are accelerated. Observations across the electromagnetic spectrum support this picture through the detection of…

High Energy Astrophysical Phenomena · Physics 2021-01-27 S. Orlando , M. Miceli , S. Ustamujic , A. Tutone , E. Greco , O. Petruk , F. Bocchino , G. Peres

Numerical solutions of the cosmic-ray (CR) magneto-hydrodynamic equations are dogged by a powerful numerical instability, which arises from the constraint that CRs can only stream down their gradient. The standard cure is to regularize by…

High Energy Astrophysical Phenomena · Physics 2018-03-16 Yan-Fei Jiang , Peng Oh

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

Cosmic-ray (CR) feedback is widely recognized as a key regulator of galaxy formation. After being accelerated at supernova remnant shocks, CRs propagate through the interstellar medium (ISM), establishing smooth large-scale distributions…

Astrophysics of Galaxies · Physics 2025-10-21 Timon Thomas , Christoph Pfrommer , Rüdiger Pakmor , Rouven Lemmerz , Mohamad Shalaby