AST1440H: Radiation

Course Summary

This course discusses the fundamental physical processes that produce and modify radiation from astrophysical sources. The astrophysical contexts within which these processes occur will also be discussed. The focus is on connecting basic electromagnetism theory with astrophysical observations.

Outline:

1. Basic Concepts
* basic radiometry; specific intensity and source function; equation of radiation transport; equivalent width and curve of growth;
* including scattering in radiation transport equation; random walk; equation of radiative diffusion, Rosseland mean opacity; blackbody radiation;
* matter LTE and radiation LTE; Einstein coefficients and inter-relation; detailed balance
* Saha-Boltzman distribution; photoionization and recombination;
* collisions: roles in reaching LTE; cross sections; critical density and critical temperature;

2. atomic and molecular transitions

3. dipole radiation and its applications
* retarded potential;
* electron scattering; scattering by dielectric medium;
* dust, Mie theory;
* Bremstruhlung