The Alfven-gravity spectrum of an incompressible slab
Abstract
The linear spectrum of a horizontal incompressible layer in the presence of a nonuniform magnetic field is studied in order to understand the dynamic stabilization of the unstable gravity modes. Such a study is necessary to understand overstable magnetic convection. Overstable magnetoconvection has been invoked as a possible mechanism for waves and oscillations in sunspots and for rapid oscillations observed in Ap-stars. The Alfven-gravity for waves and oscillations in sunspots and for rapid oscillations observed in Ap-stars. The Alfven-gravity spectrum is computed for four sequences of equilibrium configurations that differ by the profiles of the Brunt-Vaisala frequency and the Alfven frequency, and hence by the Alfven continuum. The evolution of the spectrum is determined for increasing strength of the magnetic field.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- January 1987
- Bibcode:
- 1987A&A...172...85H
- Keywords:
-
- Gravity Waves;
- Magnetohydrodynamic Stability;
- Magnetohydrodynamic Waves;
- Plasma Dynamics;
- Stellar Magnetic Fields;
- Stellar Oscillations;
- A Stars;
- Brunt-Vaisala Frequency;
- Convection;
- Incompressible Fluids;
- Plasma Slabs;
- Sunspots;
- Plasma Physics