Fundamentals of Non-relativistic Collisionless Shock Physics: IV. Quasi-Parallel Supercritical Shocks

TL;DR

This paper provides a comprehensive review of the physics of quasi-parallel supercritical collisionless shocks, including foreshock phenomena, wave modes, shock reformation, and downstream effects, integrating observations and simulations.

Contribution

It offers an extensive synthesis of observational data and simulation results on quasi-parallel shocks, highlighting recent advances and unresolved issues in shock reformation and wave interactions.

Findings

Identification of wave modes in the foreshock region

Insights into shock reformation mechanisms

Characterization of downstream shock structures

Abstract

1. Introduction, 2. The (quasi-parallel) foreshock; Ion foreshock, Ion foreshock boundary region; Diffuse ions;Low-frequency upstream waves; Ion beam waves; The expected wave modes; Observations; Diffuse ion waves; Electron foreshock; Electron beams; Langmuir waves; stability of the electron beam; Electron foreshock boundary waves; Nature of electron foreshock waves; Radiation; Observations; Interpretation; 3. Quasi-parallel shock reformation; Low-Mach number quasi-parallel shocks; Turbulent reformation; Observations; Simulations of quasi-parallel shock reformation; Hybrid simulations in 1D; Hybrid simulations in 2D; Full particle PIC simulations; Conclusions; 4. Hot flow anomalies; Observations; Models and simulations; Solitary shock; 5. Downstream region; 6. Summary and conclusions.