Compressible Relativistic Magnetohydrodynamic Turbulence in Magnetically-Dominated Plasmas And Implications for A Strong-Coupling Regime

Abstract

In this Letter, we report compressible mode effects on relativistic magnetohydrodynamic (RMHD) turbulence in Poynting-dominated plasmas using 3-dimensional numerical simulations. We decomposed fluctuations in the turbulence into 3 MHD modes (fast, slow, and Alfvén) following the procedure mode decomposition in (Cho & Lazarian 2002), and analyzed their energy spectra and structure functions separately. We also analyzed the ratio of compressible mode to Alfvén mode energy with respect to its Mach number. We found the ratio of compressible mode increases not only with the Alfvén Mach number but with the background magnetization, which indicates a strong coupling between the fast and Alfvén modes and appearance of a new regime of RMHD turbulence in Poynting-dominated plasmas where the fast and Alfvén modes strongly couples and cannot be separated, different from the non-relativistic MHD case. This finding will affect particle acceleration efficiency obtained by assuming Alfvénic critical balance turbulence, and will change the resulting photon spectra by non-thermal electrons.

5 pages, 3 figures, accepted for publication in ApJL

References in corpus (3)

• Spectral and Intermittency Properties of Relativistic Turbulence
• Magnetization degree at the jet base of M87 derived from the event horizon telescope data: Testing magnetically driven jet paradigm
• Universality and intermittency in relativistic turbulent flows of a hot plasma

Cited by in corpus (3)

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• Damping of Alfven waves by Turbulence and its Consequences: from Cosmic-Rays Streaming to Launching Winds
• Strong Coupling of Alfvén and Fast Modes in Compressible Relativistic Magnetohydrodynamic Turbulence in Magnetically-Dominated Plasmas