Diffusive Shock Acceleration with Magnetic Amplification by Non-resonant Streaming Instability in SNRs

TL;DR

This paper studies how magnetic field amplification via non-resonant streaming instability affects cosmic ray acceleration in supernova remnants, providing estimates for maximum particle energies and explaining observed magnetic field orientations.

Contribution

It combines numerical MHD simulations with analytical methods to quantify magnetic amplification and particle acceleration in supernova remnants, highlighting the role of non-resonant streaming instability.

Findings

Magnetic fields are amplified and oriented perpendicular downstream of shocks.

Maximum particle energies are estimated for several historical supernova remnants.

The amplified magnetic field explains the observed radial magnetic fields in young SNRs.

Abstract

We investigate the diffusive shock acceleration in the presence of the non-resonant streaming instability introduced by Bell (2004). The numerical MHD simulations of the magnetic field amplification combined with the analytical treatment of cosmic ray acceleration permit us to calculate the maximum energy of particles accelerated by high-velocity supernova shocks. The estimates for Cas A, Kepler, SN1006, and Tycho historical supernova remnants are given. We also found that the amplified magnetic field is preferentially oriented perpendicular to the shock front downstream of the fast shock. This explains the origin of the radial magnetic fields observed in young supernova remnants.