Stability Criteria for Massive Current Sheets in Two-dimensional Potential Magnetic Fields
Abstract
We investigate the linear stability of a simple model describing a solar prominence as a perfectly conducting vertical massive current sheet located in the 'coronal half-space' (z greater than 0), and supported against gravity by an x-invariant magnetic field. Assuming the region outside the sheet to be current-free and to contain a low-beta plasma having an infinite conductivity, and imposing the field lines to be firmly tied to the 'photospheric plane' (z = 0): (1) We show that the model is stable with respect to any perturbation which do not depend on x. (2) We derive necessary and sufficient conditions for three-dimensional stability to hold. As expected a priori, our criteria are much less severe than those Anzer obtained by taking the sheet to be embedded in a vacuum. They allow in particular -- contrary to Anzer's -- the stability of a sheet of low mass suspended in a region where the lines of the background field would have their concavity directed upward, were they unperturbed by the heavy plasma.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1994
- DOI:
- 10.1086/174617
- Bibcode:
- 1994ApJ...432..793A
- Keywords:
-
- Beta Particles;
- Current Sheets;
- Magnetic Fields;
- Solar Prominences;
- Stability;
- Stellar Models;
- Gravitational Fields;
- Magnetohydrodynamics;
- Stellar Coronas;
- Solar Physics;
- INSTABILITIES;
- MAGNETOHYDRODYNAMICS: MHD;
- PLASMAS;
- SUN: PROMINENCES