EQUILIBRIUM DISKS, MAGNETOROTATIONAL INSTABILITY MODE EXCITATION, AND STEADY-STATE TURBULENCE IN GLOBAL ACCRETION DISK SIMULATIONS
نویسندگان
چکیده
منابع مشابه
Axisymmetric Magnetorotational Instability in Viscous Accretion Disks
Axisymmetric magnetorotational instability (MRI) in viscous accretion disks is investigated by linear analysis and two-dimensional nonlinear simulations. The linear growth of the viscous MRI is characterized by the Reynolds number defined as RMRI ≡ v A/νΩ, where vA is the Alfvén velocity, ν is the kinematic viscosity, and Ω is the angular velocity of the disk. Although the linear growth rate is...
متن کاملGlobal accretion disk simulations of magneto - rotational instability
We perform global three-dimensional simulations of accretion disks integrating the compressible, non-viscous, but diffusive MHD equations. The disk is supposed to be isothermal. We make use of the ZEUS-3D code integrating the MHD equations and added magnetic diffusivity. We measure the efficiency of the angular-momentum transport. Various model simulations delivered transport parameters of α SS...
متن کاملSelf-Sustained Ionization and Vanishing Dead Zones in Protoplanetary Disks
We analyse the ionization state of the magnetohydrodynamically turbulent protoplanetary disks and propose a new mechanism of sustaining ionization. First, we show that in the quasi-steady state of turbulence driven by magnetorotational instability in a typical protoplanetary disk with dust grains the amount of energy dissipation should be sufficient for providing the ionization energy that is r...
متن کاملOrigin of nonlinearity and plausible turbulence by hydromagnetic transient growth in accretion disks: Faster growth rate than magnetorotational instability.
We investigate the evolution of hydromagnetic perturbations in a small section of accretion disks. It is known that molecular viscosity is negligible in accretion disks. Hence, it has been argued that a mechanism, known as magnetorotational instability (MRI), is responsible for transporting matter in the presence of a weak magnetic field. However, there are some shortcomings, which question the...
متن کاملNumerical Simulations of MHD Turbulence in Accretion Disks
We review numerical simulations of MHD turbulence. The last decade has witnessed fundamental advances both in the technical capabilities of direct numerical simulation, and in our understanding of key physical processes. Magnetic fields tap directly into the free energy sources in a sufficiently ionized gas. The result is that adverse angular velocity and adverse temperature gradients, not the ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2013
ISSN: 0004-637X,1538-4357
DOI: 10.1088/0004-637x/763/2/99