Relativistic Collisionless Shocks in Inhomogeneous Magnetized Plasmas

Abstract

Relativistic collisionless shocks are associated with efficient particle acceleration when propagating into weakly magnetized homogeneous media; as the magnetization increases, particle acceleration becomes suppressed. We demonstrate that this changes when the upstream carries kinetic-scale inhomogeneities, as is often the case in astrophysical environments. We use fully-kinetic simulations to study relativistic perpendicular shocks in magnetized pair plasmas interacting with upstream density perturbations. For amplitudes of $\delta \rho /\rho \gtrsim 0.5$, the upstream fluctuations are found to corrugate the shock front and generate large-scale turbulent shear motions in the downstream, which in turn are capable of accelerating particles. This can revive relativistic magnetized shocks as viable energization sites in astrophysical systems, such as jets and accretion disks. The generation of large-scale magnetic structures also has important implications for polarization signals from blazars.

8 pages, 5 figures; Accepted for publication in ApJL

References in corpus (10)

• Recent progress in astrophysical plasma turbulence from solar wind observations
• Kinetic turbulence in relativistic plasma: from thermal bath to non-thermal continuum
• Polarized Blazar X-rays imply particle acceleration in shocks
• The synchrotron maser emission from relativistic shocks in Fast Radio Bursts: 1D PIC simulations of cold pair plasmas
• Coherent Electromagnetic Emission from Relativistic Magnetized Shocks
• The synchrotron maser emission from relativistic magnetized shocks: Dependence on the pre-shock temperature
• Non-resonant particle acceleration in strong turbulence: comparison to kinetic and MHD simulations
• Saturation of the filamentation instability and dispersion measure of Fast Radio Bursts
• Filamentation of Fast Radio Bursts in magnetar winds
• Relativistic magnetohydrodynamical simulations of the resonant corrugation of a fast shock front

Cited by in corpus (3)

• The polarization of the synchrotron radiation from a recollimated jet: application to high-energy BL Lacs
• Particle acceleration and magnetic field amplification by relativistic shocks in inhomogeneous media
• Cosmic ray acceleration and non-thermal emission from fast luminous optical transient sources