The Role of Superluminal Electromagnetic Waves in Pulsar Wind Termination Shocks

Abstract

The dynamics of a standing shock front in a Poynting-flux dominated relativistic flow is investigated by using a one-dimensional, relativistic, two-fluid simulation. An upstream flow containing a circularly polarized, sinusoidal magnetic shear wave is considered, mimicking a wave driven by an obliquely rotating pulsar. It is demonstrated that this wave is converted into large amplitude electromagnetic waves with superluminal phase speeds by interacting with the shock when the shock-frame frequency of the wave exceeds the proper plasma frequency. The superluminal waves propagate in the upstream, modify the shock structure substantially, and form a well-developed precursor region ahead of a subshock. Dissipation of Poynting flux occurs in the precursor as well as in the downstream region through a parametric instability driven by the superluminal waves. The Poynting flux remaining in the downstream region is carried entirely by the superluminal waves. The downstream plasma is therefore an essentially unmagnetized, relativistically hot plasma with a non-relativistic flow speed, as suggested by observations of pulsar wind nebulae.

15 pages, 7 figures. Accepted for publication in ApJ

References in corpus (4)

• Particle acceleration in relativistic collisionless shocks: Fermi process at last?
• The Generation of Nonthermal Particles in the Relativistic Magnetic Reconnection of Pair Plasmas
• Relativistic Collisionless Shocks in Unmagnetized Electron-Positron Plasmas
• Pulsed X-ray Emission from Pulsar A in the Double Pulsar System J0737-3039

Cited by in corpus (27)

• Three-Dimensional Magnetohydrodynamic Simulations of the Crab Nebula
• Fast reconnection in relativistic plasmas: the magnetohydrodynamics tearing instability revisited
• A High-Order Relativistic Two-Fluid Electrodynamic Scheme with Consistent Reconstruction of Electromagnetic Fields and a Multidimensional Riemann Solver for Electromagnetism
• Evolution of the Relativistic Plasmoid-Chain in the Poynting-Dominated Plasma
• Cosmic-ray positrons from millisecond pulsars
• Generalized Magnetofluid Connections in Relativistic Magnetohydrodynamics
• Modelling Jets, Tori and Flares in Pulsar Wind Nebulae
• Relativistic Tearing and Drift-kink Instabilities in Two-fluid Simulations
• The inner knot of the Crab nebula
• Radiative damping and emission signatures of strong superluminal waves in pulsar winds
• Acceleration of X-ray Emitting Electrons in the Crab Nebula
• Divergence-free Approximate Riemann Solver for the Quasi-neutral Two-fluid Plasma Model
• The implications of TeV detected GRB afterglows for acceleration at relativistic shocks
• Propagation and stability of superluminal waves in pulsar winds
• A Second-order Divergence-constrained Multidimensional Numerical Scheme for Relativistic Two-Fluid Electrodynamics
• Interaction of the electro-magnetic precursor from a relativistic shock with the upstream flow. I. Synchrotron absorption of strong electromagnetic waves
• Confinement of the Crab Nebula with tangled magnetic field by its supernova remnant
• An Energy Conserving Vlasov Solver That Tolerates Coarse Velocity Space Resolutions: Simulation of MMS Reconnection Events
• Pulsar striped winds
• The Evolution of High Temperature Plasma in Magnetar Magnetospheres and its Implications for Giant Flares
• Electron acceleration at pulsar wind termination shocks
• High-order finite-difference entropy stable schemes for two-fluid relativistic plasma flow equations
• Electromagnetic spin down of a transient accreting millisecond pulsar during quiescence
• Inductive acceleration of ions in Poynting-flux dominated outflows
• Particle acceleration in superluminal strong waves
• Electromagnetic Field Theory in Superluminal Spacetime
• The stability of strong waves and its implications for pulsar wind shocks