Shchukina N. Multilevel radiative transfer and diagnostics of the solar and stellar atmospheres

The thesis deals with solution of multilevel radiative transfer problems in one and three dimensional hydrodynamic models of solar and stellar atmospheres for realistic atomic models. The optical siphoning mechanism is identified. The formation of the infrared Rydberg emission lines in the solar spectrum is explained. The NLTE abundance corrections for lithium across an extensive grid of stellar model atmospheres are specified. The NLTE FeI line formation problem in one-dimensional models of the solar atmosphere and sunspots, three-dimensional granulation models of the solar and metal -poor star atmospheres are studied. The diagnostics of the thermal structure of different solar patterns are carried out. The iron abundance problem in the solar photoshere and metal-poor star are considered. The self-consistent solutions of the kinetic and transfer equations for Fe atomic model are obtained with a new NLTE code NATAJA.