AMPLIFICATION OF GALACTIC MAGNETIC FIELDS BY THE COSMIC-RAY-DRIVEN DYNAMO

摘要

We present the first numerical model of the magnetohydrodynamic cosmic-ray-driven dynamo of the type proposed by Parker in 1992. The driving force of the amplification process comes from cosmic rays injected into the Galactic disk in randomly distributed spherical regions representing supernova remnants. The underlying disk is differentially rotating. An explicit resistivity is responsible for the dissipation of the small-scale magnetic field component. We obtain amplification of the large-scale magnetic field on a timescale of 250 Myr.