Observational signatures of particle acceleration in supernova remnants

Understand

We evaluate the current status of supernova remnants as the sources of Galactic cosmic rays.

• We summarize observations of supernova remnants, covering the whole electromagnetic spectrum and describe what these obser- vations tell us about the acceleration processes by high Mach number shock fronts.
• We discuss the shock modification by cosmic rays, the shape and maximum energy of the cosmic-ray spectrum and the total energy budget of cosmic rays in and surrounding supernova remnants.
• Additionally, we discuss problems with supernova remnants as main sources of Galactic cosmic rays, as well as alternative sources.