Can a disc dynamo generate large-scale magnetic fields?
Abstract
A dynamo process of some kind is widely believed to be able to operate in accretion discs and simple physical considerations suggest that fields generated in this way would have a canonical length-scale of the order of the disc thickness, H. However, in order to drive a hydromagnetic wind from a radius, R, it seems likely that the disc must be threaded by poloidal magnetic fields with length-scales of order R or greater. We investigate how an inverse cascade process, involving reconnection of magnetic loops above and below the disc, might, in principle, lead to large-scale fields being generated by the dynamo.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- July 1996
- DOI:
- 10.1093/mnras/281.1.219
- Bibcode:
- 1996MNRAS.281..219T
- Keywords:
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- ACCRETION;
- ACCRETION DISCS;
- MAGNETIC FIELDS