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Mean-Field Models of Galactic Dynamos Admitting Axisymmetric and Non-Axisymmetric Magnetic Field Structures

Published online by Cambridge University Press:  19 July 2016

K.-H. Rädler  and
E. Wiedemann
K.-H. Rädler
Affiliation:
Central Institute of Astrophysics DDR-1561 Potsdam, GDR
E. Wiedemann
Affiliation:
Central Institute of Astrophysics DDR-1561 Potsdam, GDR

Abstract

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A concept of mean-field models of galactic dynamos is explained in which α-effect and differential rotation act in an infinite slab of electrically conducting fluid surrounded by free space or by conducting matter at rest. Some results for α2 -dynamos are presented. In the limiting case in which the α-coefficient does not depend on the radius, axisymmetric and non-axisymmetric magnetic fields can be maintained with equal ease. For reasonable α-distributions a preference of axisymmetric fields is suggested as long as an isotropic α-effect is considered but it may disappear with anisotropic α-effect. The effect of differential rotation, which allows αω-dynamos, is briefly discussed.

Type
4. Magnetohydrodynamics of Galactic Magnetic Fields
Information
Symposium - International Astronomical Union , Volume 140: Galactic and Intergalactic Magnetic Fields , 1990 , pp. 107 - 112
Copyright
Copyright © Kluwer 1990 

References

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