Radiation Transfer and Stellar Atmospheres

This course covers the essential fundamentals needed for a solid understanding of the physics of stellar atmospheres and stellar winds. The key elements of radiation transfer theory are covered, both in local thermodynamic equilibrium (LTE) and out of LTE, as well as the description of the gas (equation of state) and its interaction with the radiation field (opacities). Modern models and simulations are presented along with their application to determining stellar parameters—particularly chemical composition—through spectroscopy. The different types of stellar winds (pressure, radiative, and hybrid) are described using theories compared with observational data.

To provide a solid foundation in radiative transfer in order to address most problems in astrophysics

Acquire a basic understanding of the physics of stellar atmospheres, enabling students to engage with specialized publications in the field

Understand the fundamental theories of stellar winds and the related mechanisms

Know how to apply this knowledge to perform calculations, estimate orders of magnitude, or test a theory.

Be familiar with the existence of the leading numerical codes for atmospheric simulation and their areas of application

Recommended prerequisites:

Fundamentals of astrophysics, quantum mechanics, atomic physics, statistical physics

Comprehensive Continuous Assessment

Advanced Radiative Transfer: ETL, non-ETL, line formation, atomic processes, radiative equilibrium, gray atmosphere

Stellar atmospheres: equations and physical components, structure, hydrostatic atmospheres, convection, 3D radiative hydrodynamic simulations, diagnostics

Stellar spectroscopy: two-level atoms, line broadening, determination of the chemical composition of atmospheres

Stellar winds: solar wind, radiative winds from hot stars, hybrid winds from red giants