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Related papers: The Effect of Cosmic Ray Diffusion on the Parker I…

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The Parker instability, a Rayleigh-Taylor like instability of thermal gas supported against gravity by magnetic fields and cosmic rays, is thought to be dynamically important for galaxy evolution, possibly promoting molecular cloud…

Astrophysics of Galaxies · Physics 2020-03-25 Evan Heintz , Chad Bustard , Ellen Zweibel

Parker instability arises from the presence of magnetic fields in a plasma in a gravitational field such as the interstellar medium (ISM), wherein the magnetic buoyant pressure expels the gas and causes the gas to move along the field…

High Energy Astrophysical Phenomena · Physics 2011-09-07 Chih-Yueh Wang , Ying-Yi Lo , Chung-Ming Ko

This study investigates Parker instability in an interstellar medium (ISM) near the Galactic plane using three-dimensional magneto-hydrodynamic simulations. Parker instability arises from the presence of a magnetic field in a plasma,…

High Energy Astrophysical Phenomena · Physics 2011-01-06 Ying-Yi Lo , Chung-Ming Ko , Chih-Yueh Wang

We present the results of linear analysis and two-dimensional local magnetohydrodynamic (MHD) simulations of the Parker instability, including the effects of cosmic rays (CRs), in magnetized gas disks (galactic disks). As an unperturbed…

Astrophysics · Physics 2009-11-10 Takuhito Kuwabara , Kenji Nakamura , C. M. Ko

We study the linear properties, nonlinear saturation and a steady, strongly nonlinear state of the Parker instability in galaxies. We consider magnetic buoyancy and its consequences with and without cosmic rays. Cosmic rays are described…

In galactic disks, the Parker instability results when non-thermal pressure support exceeds a certain threshold. The non-thermal pressures considered in the Parker instability are cosmic ray pressure and magnetic pressure. This instability…

High Energy Astrophysical Phenomena · Physics 2023-08-02 Roark Habegger , Ellen G. Zweibel , Sherry Wong

Recent studies have found that cosmic ray transport plays an important role in feedback processes such as star formation and the launching of galactic winds. Although cosmic ray buoyancy is widely held to be a destabilizing force in…

High Energy Astrophysical Phenomena · Physics 2018-06-27 Evan Heintz , Ellen G. Zweibel

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 effect of cosmic rays on the Parker-Jeans instability in magnetized self-gravitating gaseous disks is studied by three-dimensional magnetohydrodynamic (MHD) simulations with cosmic rays taken as a massless fluid with notable pressure.…

High Energy Astrophysical Phenomena · Physics 2020-08-26 Takuhito Kuwabara , Chung Ming Ko

We examine the evolution of the Parker instability in galactic disks using 3D numerical simulations. We consider a local Cartesian box section of a galactic disk, where gas, magnetic fields and cosmic rays are all initially in a…

Astrophysics of Galaxies · Physics 2015-12-24 Luiz Felippe S. Rodrigues , Graeme R. Sarson , Anvar Shukurov , Paul J. Bushby , Andrew Fletcher

We use linear analysis to examine the effect of cosmic rays (CRs) on the Parker-Jeans instability of magnetized self-gravitating gaseous disks. We adopt a slab equilibrium model in which the gravity (including self-gravity) is perpendicular…

Astrophysics · Physics 2009-11-11 Takuhito Kuwabara , Chung-Ming Ko

There is an observational correlation between astrophysical shocks and non-thermal particle distributions extending to high energies. As a first step toward investigating the possible feedback of these particles on the shock at the…

High Energy Astrophysical Phenomena · Physics 2012-01-31 Thomas Stroman , Martin Pohl , Jacek Niemiec , Antoine Bret

In the absence of magnetic fields and cosmic rays, radiative cooling laws with a range of dependences on temperature affect the stability of interstellar gas. For about four and a half decades, astrophysicists have recognised the importance…

Astrophysics of Galaxies · Physics 2011-08-08 T. W. Hartquist , A. Y. Wagner , S. A. E. G. Falle , J. M. Pittard , S. Van Loo

We present a linear perturbation analysis of the magnetorotational instability in the presence of the cosmic rays. Dynamical effects of the cosmic rays are considered by a fluid description and the diffusion of cosmic rays is only along the…

Astrophysics of Galaxies · Physics 2015-05-30 Fazeleh Khajenabi

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

Cosmic-ray transport in astrophysical environments is often dominated by the diffusion of particles in a magnetic field composed of both a turbulent and a mean component. This process, which is two-fold turbulent mixing in that the particle…

High Energy Astrophysical Phenomena · Physics 2021-12-14 P. Reichherzer , L. Merten , J. Dörner , J. Becker Tjus , M. J. Pueschel , E. G. Zweibel

Supernova energy drives interstellar medium (ISM) turbulence and can help launch galactic winds. What difference does it make if $10\%$ of the energy is initially deposited into cosmic rays? To answer this question and study cosmic-ray…

Astrophysics of Galaxies · Physics 2025-07-15 Roark Habegger , Ellen G. Zweibel

These lectures address the effects of Cosmic Rays over macro-instabilities which develop in the interstellar medium and the micro-instabilities the particles are able to trigger themselves. The lectures are centered on the derivation of…

High Energy Astrophysical Phenomena · Physics 2023-12-29 Alexandre Marcowith

We report the results of a local stability analysis for a magnetized, gravitationally stratified plasma containing cosmic rays. We account for cosmic-ray diffusion and thermal conduction parallel to the magnetic field and allow beta to take…

Astrophysics · Physics 2008-12-18 Timothy J. Dennis , Benjamin D. G. Chandran

The problem of cosmic-ray scattering in the turbulent electromagnetic fields of the interstellar medium and the solar wind is of great importance due to the variety of applications of the resulting diffusion coefficients. Examples are…

High Energy Astrophysical Phenomena · Physics 2015-05-20 R. C. Tautz
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