Turbulence and particle acceleration in a relativistic plasma

Abstract

In a collisionless plasma, the energy distribution function of plasma particles can be strongly affected by turbulence. In particular, it can develop a non-thermal power-law tail at high energies. We argue that turbulence with initially relativistically strong magnetic perturbations (magnetization parameter $\sigma \gg 1$) quickly evolves into a state with ultra-relativistic plasma temperature but mildly relativistic turbulent fluctuations. We present a phenomenological and numerical study suggesting that in this case, the exponent $\alpha$ in the power-law particle energy distribution function, $f(\gamma )d\gamma \propto {\gamma }^{-\alpha }d\gamma$, depends on magnetic compressibility of turbulence. Our analytic prediction for the scaling exponent $\alpha$ is in good agreement with the numerical results.

8 pages, 3 figures. Accepted for publication at ApJL

References in corpus (8)

• Recent progress in astrophysical plasma turbulence from solar wind observations
• Kinetic turbulence in relativistic plasma: from thermal bath to non-thermal continuum
• Collisionless Reconnection in Magnetohydrodynamic and Kinetic Turbulence
• Recent Progress on Particle Acceleration and Reconnection Physics during Magnetic Reconnectionin the Magnetically-dominated Relativistic Regime
• Particle Acceleration by Fast Modes in Solar Flares
• Corrugation of relativistic magnetized shock waves
• Linear wave propagation in relativistic magnetohydrodynamics
• Stochastic Acceleration of Electrons by Fast Magnetosonic Waves in Solar Flares: the Effects of Anisotropy in Velocity andWavenumber Space