Cosmic-ray acceleration in supernova shocks

Understand

Galactic cosmic rays are widely believed to be accelerated in expanding shock waves initiated by supernova explosions.

• The theory of diffusive shock acceleration of cosmic rays is now well established, but two fundamental questions remain partly unanswered: what is the acceleration efficiency, i.e.
• the fraction of the total supernova energy converted to cosmic-ray energy, and what is the maximum kinetic energy achieved by particles accelerated in supernova explosions? Recent observations of supernova remnants, in X-rays with the Chandra and XMM-Newton satellites and in very-high-energy gamma rays with several ground-based atmospheric Cerenkov telescopes, have provided new pieces of information concerning these two questions.
• After a review of these observations and their current interpretations, I show that complementary information on the diffusive shock acceleration process can be obtained by studying the radio emission from extragalactic supernovae.