Particle Acceleration in Supernova Remnants and the Production of Thermal and Nonthermal Radiation

Energetic particle production in supernova remnants (SNRs) through diffusive shock acceleration has long been suggested as a mechanism by which the bulk of cosmic rays with energies less than ∼ 10 eV are formed. If highly efficient, this process can have a significant effect on the X-ray emission from SNRs as well as their dynamical evolution. Here we investigate the expected modification to the thermal X-ray emission from the forward shock region of young SNRs in which efficient particle acceleration is occurring. Using hydrodynamical simulations for a range of ambient density and magnetic field values, we produce spectra for both the thermal and nonthermal emission components of the postshock gas. For a given ambient density and explosion energy, we find that the position of the forward shock at a given age is a strong function of the acceleration efficiency, providing a strong signature of cosmic ray production. Using an