BEXCO - Room A(101/102)
[CRD006] Particle acceleration by pulsar wind nebulae inside supernova remnants
The origin of cosmic-ray (CR) PeVatrons is a long standing problem in the Astrophysics. The CR spectrum has a spectral break at about 1 PeV (so called, the knee energy). The diffusive shock acceleration at supernova remnants (SNRs) is believed to be the acceleration mechanism of CRs up to the knee energy. However, there are still many problems. One is the knee problem. It was estimated that SNRs cannot accelerate CRs to the knee energy for a parallel shock without magnetic field amplification. We propose that CR PeVatrons are pulsar wind nebulae (PWNe) inside SNRs. The PWN initially expands into the free expanding stellar ejecta. Then, the PWN catches up with the shocked region of the SNR, where particles can be slightly accelerated by the back and forth motion between the PWN and the SNR, and some particles diffuse into the PWN. Afterwards the PWN is compressed by the SNR, where the particles in the PWN are accelerated by the adiabatic compression. By using a Monte Carlo simulation, we show that particles accelerated by the SNR to 0.1 PeV can be reaccelerated to 1 PeV until the end of the PWN compression.