Physics / advanced
Radiation and matter in astrophysical environments
Develop emission, absorption, scattering, and gas-dynamical processes needed to interpret spectra and energy transport across astrophysical sources.
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Inside this module
Module 01 advanced
Radiation and matter in astrophysical environments
Develop emission, absorption, scattering, and gas-dynamical processes needed to interpret spectra and energy transport across astrophysical sources.
- 01
Radiative transfer equation and optical depth
Define directional spectral radiation quantities, fix the transfer sign along a ray, and distinguish ray optical depth from a slab's normal optical depth.
28 min - 02
Emission, absorption, and source functions
Solve a uniform emitting slab, separate true absorption from scattering, and connect line coefficients to populations without silently assuming LTE.
29 min - 03
Local thermodynamic equilibrium and Kirchhoff's law
Apply thermal detailed balance without assuming a globally Planckian radiation field, and distinguish kinetic, excitation and brightness temperatures.
29 min - 04
Atomic line formation and the curve of growth
Separate line opacity, broadening and equivalent width, then identify the linear, saturated-core and damping-wing growth regimes.
29 min - 05
Free-free emission and absorption
Connect thermal bremsstrahlung to absorption, emission measure and clumping with an explicit Maxwellian nonrelativistic regime.
28 min - 06
Synchrotron emissivity and self-absorption
Connect relativistic electron energies and magnetic fields to continuum slopes while stating the assumptions behind homogeneous synchrotron self-absorption.
29 min - 07
Inverse Compton scattering and the Klein–Nishina limit
Estimate photon boosts and electron losses in the Thomson regime, then diagnose where recoil invalidates those estimates.
29 min - 08
Photoionization equilibrium and H II regions
Distinguish total-field ionization balance from the Case B photon budget and derive a static hydrogen ionized-region scale.
30 min - 09
Radiative cooling functions and thermal instability
Define cooling normalization and energy content, then derive distinct isochoric and isobaric stability criteria for an explicit toy heating law.
31 min - 10
Eddington luminosity and radiation-supported flow
Derive an opacity-dependent radiation-force scale and separate hydrostatic balance from a closed outflow calculation.
30 min