Amplification of galactic magnetic fields by the cosmic-ray-driven dynamo

被引:95
作者
Hanasz, M [1 ]
Kowal, G
Otmianowska-Mazur, K
Lesch, H
机构
[1] Nicholas Copernicus Univ, Torun Ctr Astron, PL-87148 Piwnice Torun, Poland
[2] Jagiellonian Univ, Astron Observ, PL-30244 Krakow, Poland
[3] Univ Munich, Univ Observ, D-81679 Munich, Germany
关键词
cosmic rays; galaxies : ISM; galaxies : magnetic fields; magnetic fields; MHD;
D O I
10.1086/420697
中图分类号
P1 [天文学];
学科分类号
0704 ;
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.
引用
收藏
页码:L33 / L36
页数:4
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