Particle acceleration at quasi-perpendicular non-relativistic high Mach number shocks

Abstract

Electron and ion acceleration at a non-relativistic collisionless shocks is studied by employing large scale one-dimensional particle-in-cell (PIC) simulations in the de-Hoffmann and Teller (dHT) frame of reference. We demonstrate that diffusive shock acceleration of both electrons and ions occurs in quasi-perpendicular shock configurations at large Alfvén Mach numbers. We also identify the role of precursor waves on the electron energization in the upstream region. The emergence of a significant non-thermal ion component holds important implications for observations of hadronic emission from collisionless shocks occurring for example in supernova remnants, and colliding stellar winds.

Non-thermal particle acceleration at highly oblique non-relativistic shocks

“…This suggests the long-term evolu-tion of the shock dynamics and particle acceleration is the same in different frames using alternative setups. A more direct comparison can be made between the present results, performed in the SNF, with matching simulations (using the relaxation setup) performed in the de-Hoffman and Teller frame (dHT) (Kumar & Reville 2021). This frame is ideal for acceleration studies since both the shock and the zeroth-order field lines are static (in the SNF, field lines are continuously dragged across the shock).…”

“…These two frames are related by an appropriate Lorentz boost along the shock surface. While the runtimes for results presented in Kumar & Reville (2021) were shorter, compatible spectra are found at these times, when corrected for frame transformations. 1 However, in Lorentz transforming, the 1D simulation probes a different k-vector of the upstream plasma dispersion.…”