Radiation-hydrodynamic waves in an optically grey atmosphere. II. Analysis of wave properties and effects of thermal conductivity in a homogeneous model.
Abstract
The properties of radiation-hydrodynamic waves in a radiative, thermally conducting, uniform atmosphere are investigated, avoiding the Eddington approximation and considering a temporal as well as a spatial analysis. The analysis of the dispersion equation shows the existence of acoustic, radiation, and thermal wave modes and a relaxation mode as well. The generalized Spiegel formula is discussed and the accuracy of the Eddington approximation for the radiation-hydrodynamic waves is considered. The amplitudes and phases of disturbances of gas and radiation pressure, intensity, and temperature are obtained for standing and travelling waves and for the relaxation mode too. The polar angle dependence of the phase shift between velocity and intensity is investigated. The predictions for full-disk intensity observations and the deficiencies of earlier, less complete approaches are discussed.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- November 1994
- Bibcode:
- 1994A&A...291.1001D
- Keywords:
-
- Hydrodynamics;
- Photosphere;
- Radiative Transfer;
- Solar Oscillations;
- Wave Propagation;
- Local Thermodynamic Equilibrium;
- Phase Velocity;
- Radiation Pressure;
- Wave Dispersion;
- Solar Physics;
- HYDRODYNAMICS;
- RADIATIVE TRANSFER;
- SUN: OSCILLATIONS;
- SUN: PHOTOSPHERE