Radiative Transfer and Stellar Atmospheres
- Radiation field: Definitions, energy
density, radiation pressure.
- Equation of transfer: Interaction of
radiation and matter, transfer equation, angular
moments, radiative equilibrium, diffusion
- Grey atmosphere problem: Definition, mean
opacities. approximate solutions.
- LTE equation of state.
- Absorption cross section: Einstein
coefficients, continuous absorption and scattering
- Solution of the transfer equation.
- LTE model atmosphere: Assumptions,
boundary value problem.
- Statistical equilibrium: Requirements for
LTE, non-LTE rate equations.
- Non-LTE model atmosphere for early-type
- Line formation: Observable quantities,
line profiles, Voigt function.
- Classical treatment of line formation: Milne-Eddington model, curve of growth, LTE
- Non-LTE line formation: Two level atom
with and without continuum, multilevel atoms.
- Radiative transfer with macroscopic velocity fields: Modified transfer equation with velocity fields, co-moving frame approach, Sobolev approximation, escape probabilities, and non-LTE.
- Stellar winds: Hydrodynamic equations of radiation-driven winds, line and continuum radiative forces, critical points and singularities, analytical and numerical solutions.
This outline is representative only, and is likely to change from instructor to instructor and from year to year.