## Swing excitation of magnetic fields in trailing spiral galaxies?
Swing-excited dynamo-induced magnetic fields in spiral galaxies are studied. We investigate the phenomenon of swing excitation with linear and nonlinear 3D numerical simulations of the galactic dynamo. The model includes differential rotation, axisymmetric and isotropic -effect and uniform eddy diffusivity. The nonaxisymmetry is introduced via large-scale radial and azimuthal velocity components associated with a spiral density-wave perturbation. In a first step we present a linear analysis in order to get
insight in basic properties of the swing-excitation phenomenon. Both
one and two-armed spiral galaxies are investigated. We find enlarged
growth rates for the magnetic energy connected with the parametric
resonance condition
( pattern speed,
magnetic drift rate), but only if the
amplitude of the perturbation exceeds 10 km s
## Contents- 1. Introduction
- 2. The mean-field electrodynamics
- 3. The model
- 4. Growth rates and magnetic field drift
- 5. The nonlinear regime
- 6. Conclusion
- Acknowledgements
- References
© European Southern Observatory (ESO) 1999 Online publication: June 6, 1999 |