TY - JOUR

T1 - Acceleration of relativistic electrons by magnetohydrodynamic turbulence

T2 - Implications for non-thermal emission from black hole accretion disks

AU - Lynn, Jacob W.

AU - Quataert, Eliot

AU - Chandran, Benjamin D.G.

AU - Parrish, Ian J.

PY - 2014/8/10

Y1 - 2014/8/10

N2 - We use analytic estimates and numerical simulations of test particles interacting with magnetohydrodynamic (MHD) turbulence to show that subsonic MHD turbulence produces efficient second-order Fermi acceleration of relativistic particles. This acceleration is not well described by standard quasi-linear theory but is a consequence of resonance broadening of wave-particle interactions in MHD turbulence. We provide momentum diffusion coefficients that can be used for astrophysical and heliospheric applications and discuss the implications of our results for accretion flows onto black holes. In particular, we show that particle acceleration by subsonic turbulence in radiatively inefficient accretion flows can produce a non-thermal tail in the electron distribution function that is likely important for modeling and interpreting the emission from low-luminosity systems such as Sgr A* and M87.

AB - We use analytic estimates and numerical simulations of test particles interacting with magnetohydrodynamic (MHD) turbulence to show that subsonic MHD turbulence produces efficient second-order Fermi acceleration of relativistic particles. This acceleration is not well described by standard quasi-linear theory but is a consequence of resonance broadening of wave-particle interactions in MHD turbulence. We provide momentum diffusion coefficients that can be used for astrophysical and heliospheric applications and discuss the implications of our results for accretion flows onto black holes. In particular, we show that particle acceleration by subsonic turbulence in radiatively inefficient accretion flows can produce a non-thermal tail in the electron distribution function that is likely important for modeling and interpreting the emission from low-luminosity systems such as Sgr A* and M87.

KW - acceleration of particles accretion

KW - accretion disks plasmas

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U2 - 10.1088/0004-637X/791/1/71

DO - 10.1088/0004-637X/791/1/71

M3 - Article

AN - SCOPUS:84905171680

SN - 0004-637X

VL - 791

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 1

M1 - 71

ER -