Cosmic-ray driven dynamo in galactic disks

Abstract

We present new developments on the Cosmic--Ray driven, galactic dynamo, modeled by means of direct, resistive CR--MHD simulations, performed with ZEUS and PIERNIK codes. The dynamo action, leading to the amplification of large--scale galactic magnetic fields on galactic rotation timescales, appears as a result of galactic differential rotation, buoyancy of the cosmic ray component and resistive dissipation of small--scale turbulent magnetic fields. Our new results include demonstration of the global--galactic dynamo action driven by Cosmic Rays supplied in supernova remnants. An essential outcome of the new series of global galactic dynamo models is the equipartition of the gas turbulent energy with magnetic field energy and cosmic ray energy, in saturated states of the dynamo on large galactic scales.

6 pages, 3 figures, To be published in "Cosmic Magnetic Fields: From Planets, to Stars and Galaxies", K.G. Strassmeier, A.G. Kosovichev & J.E. Beckman, eds., Proc. IAU Symp. 259, CUP

References in corpus (10)

• Origin of Galactic and Extragalactic Magnetic Fields
• Magnetic Field Structure and Stochastic Reconnection in a Partially Ionized Gas
• Direct simulations of a supernova-driven galactic dynamo
• A Global Probe of Cosmic Magnetic Fields to High Redshifts
• Amplification of Galactic Magnetic Fields by the Cosmic-Ray Driven Dynamo
• $10^{51}$ Ergs: The Evolution of Shell Supernova Remnants
• The Effect of Cosmic Ray Diffusion on the Parker Instability
• A Model for Spontaneous Onset of Fast Magnetic Reconnection
• A Free, Fast, Simple and Efficient TVD MHD Code
• Discussion of the Electromotive Force Terms in the Model of Parker-unstable Galactic Disks with Cosmic Rays and Shear

Cited by in corpus (4)

• Interstellar magnetic fields in the Galactic center region
• Cosmic rays and the magnetic field in the nearby starburst galaxy NGC 253: II. The magnetic field structure
• The large scale magnetic field structure of the spiral galaxy NGC 5775
• PIERNIK mhd code - a multi-fluid, non-ideal extension of the relaxing-TVD scheme (IV)