Coherent Electromagnetic Emission from Relativistic Magnetized Shocks

Area of Science:

• Plasma physics
• Astrophysics
• Computational physics

Background:

• Relativistic magnetized shocks are theorized to produce coherent emission.
• This emission is a potential mechanism for Fast Radio Bursts (FRBs).
• Understanding shock properties is crucial for FRB models.

Purpose of the Study:

• To investigate the emission efficiency, spectrum, and polarization from relativistic magnetized shocks.
• To provide essential data for shock-based FRB models.
• To elucidate the emission mechanisms of X and O modes.

Main Methods:

• First-principles 3D particle-in-cell simulations.
• Simulations of shocks propagating in electron-positron (e^{±}) plasma.
• Analysis of plasma magnetization (σ>1) effects on emission.

Main Results:

• Emission efficiency is approximately 10^{-3}σ^{-1} of shock energy.
• Energy-carrying wave number of the spectrum is around 4ω_{c}/c.
• O-mode to X-mode energy flux ratio is approximately 0.4σ^{-1}, with X-mode dominance at high σ.

Conclusions:

• Relativistic magnetized shocks are a viable source for FRB emission.
• Simulation results quantify key emission properties.
• The dominance of X-mode emission at high magnetization is a significant finding for FRB models.