Recent observational studies on particle acceleration in supernova remnants

Supernova remnants (SNRs) have long been regarded as major production sites of Galactic cosmic rays. Recent high energy gamma-ray observations by AGILE and Fermi LAT have proved that protons, which dominate the composition of Galactic cosmic rays, are indeed accelerated in shocks of SNRs through detection of emission from neutral pion decay. X-ray and very high energy gamma-ray observations, on the other hand, have been providing evidence that charged particles are accelerated beyond TeV energies in SNRs. Yet, there are still open questions left to be solved such as whether or not SNR shocks are able to accelerate particles up to the knee of the cosmic-ray spectrum at ~ PeV, and what is the total energy of cosmic rays that each SNR can produce. I will review recent observational results and their implications about particle acceleration in SNR shocks. I also will talk about prospects from near future observations with, for example, XRISM, Athena, and CTA.