California State University at Northridge

Department of Physics and Astronomy

18111 Nordhoff St, Northridge, CA 91330

wlyra - nospam - csun.edu

+1 818-677-7464

Lectures for the course *Selected Topics in Astrophysics*, a graduate course at CSUN.

**Part 1: Radiative Transfer**- Class 1
- Syllabus and overall overview. Preliminaries: parallax, magnitudes, spectral sequence, HR diagram.

- Class 2 [ppt] [notes]
- Principles of Radiative Transfer

- Class 3 [ppt] [notes]
- Emission and absorption, opacity, radiative transfer equation, Kirchhoff laws.

- Class 4 [notes]
- Einstein coefficients, scattering, plane-parallel approximation, radiative equilibrium.

- Material from :
- An Introduction to Modern Astrophysics, Carroll & Ostlie
- Stellar Interiors, Hansen & Kawaler
- Introduction to Stellar Astrophysics, Erika Bohm-Vitense
- Radiative Processes in Astrophysics, Rybicki & Lightman
- Astrophysics for Physicists, Choudhuri

- Class 1
**Part 2: Stellar Structure**- Class 5 [notes]
- Gray approximation, Rossland approximation, Rossland vs Planck opacities, Eddington approximation, introduction to stellar structure (mass continuity and hydrostatic equilibrium equations).

- Class 6 [ppt] [notes]
- Stellar structure: virial theorem, gravitational contraction, luminosity and temperature equation (radiative).

- Class 7 [notes]
- Convection. Schwarschild criterion. Full equations of stellar structure.

- Material from : Same as 1.

- Class 5 [notes]
**Part 3: Stellar Evolution**- Class 8 [ppt] [notes]
- Nucleosynthesis (Reaction cross sections, Gamow peak, nuclear reaction rates, proton-proton chain, CNO cycle, triple alpha)

- Class 9 [ppt] [notes]
- Evolution of low mass stars (Evolution in the main sequence, shell burning, subgiant branch, degeneracy, degenerate pressure -- nonrelativistic and relativistic --, Fermi energy, red giant branch, Helium flash, helium burning, horizontal branch, asymptotic giant branch, thermal pulses, planetary nebula, white dwarf).

- Class 10 [ppt] [notes]
- Evolution of high mass stars (Core-collapse supernova, carbon burning, alpha ladder, photodisintegration, origin of odd-Z elements, neutronization, core collapse, core rebound, neutrino opacity, blastwave, supernova).

- Class 11 [ppt - Slides by Prof Christian] [notes]
- Lane-Emden equation, Chandrasekhar limit.

- Material from:
- An Introduction to Modern Astrophysics, Carroll & Ostlie
- Stellar Interiors, Hansen & Kawaler
- Astrophysics for Physicists, Choudhuri

- Class 8 [ppt] [notes]
**Part 4: Planet Formation**- Class 12 [ppt] [notes]
- Star formation: Jeans criterion. Jeans mass and Jeans length. Circumstellar disks, Bonnor-Ebert mass.

- Class 13 [ppt] [notes]
- Tides, Roche limit. Gravitational collapse: planetesimals.

- Class 14 [ppt] [notes]
- Planet formation: Core accretion. Hill radius, isolation mass, gravitational focusing, critical core mass.

- Class 15 [ppt] [notes]
- Interiors: inertia moment, gravitational moments. Planet formation: Gravitational Instability. Toomre instability analysis. Toomre parameter.

- Class 16 and 17 [ppt16] [ppt17] [notes]
- Planet-disk interaction: migration. Impulse approximation. Lindblad resonances. Gap opening.

- Material from:
- Carroll & Ostlie, An Introduction to Modern Astrophysics, Chapter 19 (tides), Chapter 21 (Giant planets).
- De Pater & Lissauer, Planetary Sciences, Chapter 2.5 (oblateness, gravitational moments). Chapter 13 (planet formation problems)
- Murray & Dermott, Solar System Dynamics, Problem 4.2 for homework assignment.
- Armitage, Astrophysics of Planet Formation.

- Class 12 [ppt] [notes]
**Part 5: Planet interiors and atmospheres**- Class 18 [ppt] [notes]
- Interiors of giant planets, n=1 polytrope, degeneracy parameter, pressure ionization. Planet's equilibrium temperature, greenhouse-corrected temperature.

- Class 19 [ppt] [notes]
- Atmospheres: Hadley circulation, storm systems, vorticity conservation. Icy moons: subsurface oceans, tidal dissipation, radiogenic heating.

- Sample latex file
- Code in IDL for solution of homework #6
- Code in Python for solution of homework #6

- Material from:
- de Pater, I. & Lissauer, J.: Planetary Sciences.
- Guillot, T.: Physics of Substellar Objects: Interiors, Atmospheres, Evolution.

- Class 18 [ppt] [notes]
**Part 6: Magnetohydrodynamics**- Class 20 [notes]
- Gaussian units, local neutrality, Debye length, magnetic tension and magnetic pressure, induction equation, magnetic Reynolds number.

- Class 21 [notes]
- Alfvén's flux-freezing theorem. Alfvén wave.

- Class 22 [pdf] [notes]
- Solar wind. Parker model. Parker spiral.

- Material from:
- Choudhuri, A.R., The Physics of Fluids and Plasmas: An Introduction for Astrophysicists.
- Goossens, M., An Introduction to Plasma Astrophysics and Magnetohydrodynamics.
- Sturrock, P.A., Plasma Physics: An Introduction to the Theory of Astrophysical, Geophysical, and Laboratory Plasmas.

- Class 20 [notes]
**Part 7: Cosmology**- Class 23 [ppt] [handout]
- Introduction to galaxies and cosmology (class by Prof Christian).

- Class 24 [notes]
- Hubble law, scale factor, redshift, Friedmann equation, age of Universe.

- Class 25 [notes]
- Fluid equation, acceleration equation, dark energy, early universe, radiation, matter, and dark energy-dominated eras.

- Class 26 [ppt] [notes]
- Dark matter.

- Material from Carroll & Ostlie's BOB.

- Class 23 [ppt] [handout]