Department of Physics

18309  Plasma Astrophysics

Course Webpage: https://eclass.uoa.gr/courses/PHYS345/

Course Content

• Steady magnetized flows with an ignorable coordinate. Magnetohydrodynamic (MHD) waves (Alfvèn, fast and slow magnetosonic waves).
• Magnetized winds and angular momentum extraction in young stellar objects, Weber-Davis model.
• Jeans gravitational instability. Star formation, angular momentum, magnetic flux and efficiency problems, evolution of stellar rotation, magnetic critical collapse mass, Skumanich's law.
• Astrophysical jets. Minimum inclination of outflow fieldlines with respect to the axis of rotation. Collimation of MHD outflows and examples.
• Self-similarity. Families of models for describing self-similar MHD jets. Critical points, separatrix surfaces and causality in MHD outflows. Collimation criteria.
• Method of characteristics (steady supersonic flow, Riemann invariants). Magnetohydrodynamic shock waves. Magnetic dynamo. Magnetic reconnection.  
• Relativistic magnetohydrodynamics, applications to γ-ray bursts and jets from active galactic nuclei.
• Instabilities (Rayleigh-Taylor, Kelvin-Helmholtz, pinch, kink, Parker, magnetorotational).
• Kinetic theory for collisionless magnetized plasmas. Plasma oscillations and Landau damping.