The Generation of Magnetic Fields in Astrophysical Bodies.VI. Periodic Modes of the Galactic Field
Abstract
It is shown from the dynamo equations that the cyclonic turbulence and nonuniform rotation of the gaseous disk of the Galaxy generate magnetic field in both periodic and nonperiodic modes. Order-ofmagmtude estimates of the dynamo number suggest that the large-scale galactic field is generated in the lowest even periodic and/or nonperiodic modes. The characteristic period of the periodic mode is estimated at 108 years. The large amplitude of the small-scale (lO pc) fluctuations in the internal field of the Galaxy make it difficult to compare the local field observations with theory to designate the mode of the large-scale field extending throughout the disk.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1971
- DOI:
- 10.1086/150958
- Bibcode:
- 1971ApJ...166..295P