High Energy Astrophysics

This course is an introduction to the acceleration, propagation and radiation mechanisms of energetic particles in astrophysical media. It will give the fundamental concepts.

To acquire the basic notions on the acceleration and propagation processes of astroparticles in magnetized media. The course will be given in lecture form, but accompanied by exercises with their answers, to be done at home in addition. A reading sheet of a short journal on cosmic rays will also be requested to get familiar with the reading of articles.

To acquire essential knowledge of the mechanisms of energetic particle radiation in astrophysical media, including synchrotron, Bremsstrahlung, inverse Compton and pi-meson production. These processes will be presented in lecture form, but the course will aim to develop the practical application of this knowledge in problem solving.

Prerequisites*:

Fluid mechanics, electromagnetism, special relativity.

Recommended Prerequisites:

Plasma physics, Hamiltonian dynamics, analytical mechanics, magnetohydrodynamics.

CCI 100%: Written exam with documents (3h) + Reading sheet to be handed in. The grade will be the max between the exam grade and the weighted average of the exam with the reading sheet.

^1st series course :

- Review on cosmic radiation.

- Motion of a charged particle in a uniform magnetic field: Larmor motion, effect of an electric field, case of drift of the guide center produced by an external force perpendicular to the magnetic field, drift of the guide center produced by a gradient of the magnetic field: magnetic moment of the particle. The first adiabatic invariant of motion in a non uniform magnetic field and the magnetic mirror.

- Derivation of the Vlasov equation from Klimontovich, the non-relativistic and relativistic Vlasov equation, the Landau effect, an introduction to the Fokker-Planck equation

- Derivation of the ideal MHD equations from Vlasov, one- and two-fluid equations and generalized Ohm's law, Alfvén's theorem.

- Magnetic reconnection, Sweet-Parker model and two words about Petschek

- The Hillas confinement formula, Fermi acceleration processes of 2nd and 1st order (case of a shock wave).

- The quasi-linear theory of cosmic ray transport.

^2nd set of classes :

- Radiation from accelerated charges: classical electrodynamics, relativistic generalization

- Emission Bremsstrahlung

- Synchrotron radiation

- Applications: cosmic electrons

- Quantum processes: Inverse Compton, hadronic emission

- Applications: supernova remnant