Identifying the accelerators of Galactic cosmic ray (CR) protons with energies up to a few PeV remains a theoretical and observational challenge. Supernova remnants (SNRs) represent strong candidates because they provide sufficient energetics to reproduce the CR flux observed at Earth. Moreover, their strong forward shocks provide an efficient means of accelerating particles: diffusive shock...
Observations have established supernova remnants (SNRs) as efficient accelerators of cosmic rays, in particular electrons. Whereas the acceleration process is known in principle, many aspects are poorly understood. In fact, a number of central points that were considered certain twenty years ago have since had to be discarded. It is still unclear how the soft production spectrum required by...
