High Energy Astrophysics

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

Acquire a basic understanding of the acceleration and propagation of astroparticles in magnetized media. The course will be given in lecture form, but accompanied by exercises with their answers, to be completed at home. A reading sheet from a short journal on cosmic rays will also be required to familiarize students with the reading of articles.

Acquire essential knowledge of energetic particle radiation mechanisms in astrophysical environments, 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 due. The grade will be the max between the exam grade and the weighted average of the exam with the reading sheet.

^1st course series :

- Review of cosmic rays.

- 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 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

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

- Quasi-linear theory of cosmic ray transport.

^2nd course series :

- Radiation from accelerated charges: classical electrodynamics, relativistic generalization

- Bremsstrahlung emission

- Synchrotron radiation

- Applications: cosmic electrons

- Quantum processes: inverse Compton, hadronic emission

- Applications: supernova remnant