Kinetic simulations of imbalanced turbulence in a relativistic plasma: Net flow and particle acceleration
ABSTRACT Turbulent high-energy astrophysical systems often feature asymmetric energy injection: for instance, Alfvén waves propagating from an accretion disc into its corona. Such systems are ‘imbalanced’: the energy fluxes parallel and antiparallel to the large-scale magnetic field are unequal. In the past, numerical studies of imbalanced turbulence have focused on the magnetohydrodynamic regime. In this study, we investigate externally driven imbalanced turbulence in a collision-less, ultrarelativistically hot, magnetized pair plasma using 3D particle-in-cell (PIC) simulations. We find that the injected electromagnetic momentum efficiently converts into plasma momentum, resulting in net motion along the background magnetic field with speeds up to a significant fraction of lightspeed. This discovery has important implications for the launching of accretion disc winds. We also find that although particle acceleration in imbalanced turbulence operates on a slower time-scale than in balanced turbulence, it ultimately produces a power-law energy distribution similar to balanced turbulence. Our results have ramifications for black hole accretion disc coronae, winds, and jets.
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Award ID(s):
Publication Date:
NSF-PAR ID:
10329475
Journal Name:
Monthly Notices of the Royal Astronomical Society
Volume:
509
Issue:
3
Page Range or eLocation-ID:
3826 to 3841
ISSN:
0035-8711
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