3D Magneto-Hydrodynamic Simulations of Parker Instability with Cosmic Rays

Abstract

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, wherein the magnetic buoyant pressure expels the gas and cause the gas to move along the field lines. The process is thought to induce the formation of giant molecular clouds in the Galaxy. In this study, the effects of cosmic-ray (CR) diffusion are examined. The ISM at equilibrium is assumed to comprise a plasma fluid and a CR fluid at various temperatures, with a uniform magnetic field passing through it in the azimuthal direction of the Galactic disk. After a small perturbation, the unstable gas aggregates at the footpoint of the magnetic fields and forms dense blobs. The growth rate of the instability increases with the strength of the CR diffusion. The formation of dense clouds is enhanced by the effect of cosmic rays (CRs), whereas the shape of the clouds depends sensitively on the initial conditions of perturbation.

4 pages, Computer Physics Communications 2011, 182, p177-179

References in corpus (4)

• Amplification of Galactic Magnetic Fields by the Cosmic-Ray Driven Dynamo
• Nonlinear Parker Instability with the Effect of Cosmic-Ray Diffusion
• Three-Dimensional Evolution of the Parker Instability under a Uniform Gravity
• Can the cosmic-ray driven dynamo model explain the observations of the polarized emission of edge-on galaxies ?

Cited by in corpus (4)

• Rayleigh-Taylor Instabilities in Type Ia Supernova Remnants undergoing Cosmic-Ray Particle Acceleration - Low Adiabatic Index Solutions
• Dynamics of the Parker-Jeans instability of gaseous disks including the effect of cosmic rays
• Outflows in the presence of cosmic rays and waves
• Outflows in the presence of cosmic rays and waves with cooling