Radiation Transfer and Stellar Atmospheres

This course covers the essentials needed to understand the physics of stellar atmospheres and winds. The essential elements of radiation transfer theory are covered, both at ETL (local thermodynamic equilibrium) and outside ETL, 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 the determination of stellar parameters, in particular chemical composition, via spectroscopy. The different types of stellar wind (pressure, radiative, hybrid) are described by comparing theories with observations.

Provide a fundamental grounding in radiative transfer to tackle most astrophysical problems

Acquire a basic understanding of the physics of stellar atmospheres, enabling you to tackle specialized publications in the field.

Understand the basic theories of stellar winds and their mechanisms

Apply this knowledge to perform calculations, estimate orders of magnitude, or test a theory.

Know the existence of emblematic numerical codes for simulating atmospheres and their field of application

Recommended prerequisites:

Basic astrophysics, quantum mechanics, atomic physics, statistical physics

Continuous control

Advanced radiative transfer: ETL, off-ETL, line formation, atomic processes, radiative balance, grey atmosphere

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

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

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