Cosmic-ray acceleration in a supernova remnant shock propagating in a stellar wind with a wind termination shock

Abstract

We investigate the acceleration process of particles in core-collapse supernova remnants (SNRs) propagating in the circumstellar medium with the Parker-spiral magnetic field, current sheet, and wind termination shock (WTS). Wolf-Rayet (WR) stars are considered in this work as progenitors of supernovae. Test particle simulations are performed to reveal the particle motion between the SNR shock and WTS and attainable maximum energy without magnetic field amplification in the upstream region, where the magnetic field strength and rotation period expected from observations of WR stars are used. We show that particles can experience the cyclic motion between the SNR shock and WTS until the SNR shock collides with the WTS. Particles are accelerated at the SNR shock and WTS again and again and the attainable maximum energy can exceed the maximum energy limited by escape from core-collapse SNRs.