Syllabus of lectures

A brief review of solar and stellar spectroscopy.

Basics of radiative transfer: absorption and emission of radiation, source function, optical depth, radiative-transfer equation, simple illustrative solutions, Eddington-Barbier relation.

Two-level atom: basic processes, statistical equilibrium, LTE versus non-LTE, solutions for semi-infinite atmosphere, basic properties (thermalization of radiation).

Numerical solutions of the radiative-transfer equation coupled to statistical equilibrium: Feautrier method, iterative methods (ALI, MALI).

Multilevel atoms: general kinetic equilibrium, radiative and collisional rates, ionization/ recombination processes, Milne-Einstein relations for continuum, radiation losses.

Spectral line broadening, scattering of line radiation, partial redistribution.

Line formation in solar and stellar atmospheres, source-function variations, emergent line shapes (lines in absorption/emission, line reversals, line asymmetries due to flows), optically-thin UV lines (CHIANTI code), synthetic radio spectra in the ALMA range.

Basic equations of solar and stellar atmospheric modeling (hydrostatic equilibrium, radiative equilibrium, non-LTE equations), illustrative solutions for gray atmosphere, line blanketing.

Brief review of static and semi-empirical atmospheric models, solar and stellar examples, modeling of solar/stellar flares and prominences.

A review of numerical codes for atmospheric modeling, test-runs with the MALI code.

Basics of radiation-hydrodynamics (RHD), numerical RHD codes (e.g. FLARIX, RADYN),example of time-dependent atmospheric modeling.