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Related papers: Emergent Mesoscale Phenomena in Magnetized Accreti…

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Grid-based magnetohydrodynamic (MHD) simulations have proven invaluable for the study of astrophysical accretion disks. However, the fact that angular momentum transport in disks is mediated by MHD turbulence (with structure down to very…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Kareem A. Sorathia , Christopher S. Reynolds , James M. Stone , Kris Beckwith

We analyze a suite of global magnetohydrodynamic (MHD) accretion disk simulations in order to determine whether scaling laws for turbulence driven by the magnetorotational instability, discovered via local shearing box studies, are globally…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Kareem A. Sorathia , Christopher S. Reynolds , Philip J. Armitage

We investigate the significance of large scale azimuthal, magnetic and velocity modes for the MRI turbulence in accretion disks. We perform 3D global ideal MHD simulations of global stratified proto-planetary disk models. Our domains span…

Solar and Stellar Astrophysics · Physics 2015-05-30 M. Flock , N. Dzyurkevich , H. Klahr , N. Turner , Th. Henning

(Abridged) We report results of three dimensional MHD simulations of global accretion disks threaded with weak vertical magnetic fields. We perform the simulations in the spherical coordinates with different temperature profiles and…

Earth and Planetary Astrophysics · Physics 2015-06-17 Takeru K. Suzuki , Shu-ichiro Inutsuka

Magnetorotational turbulence provides a viable mechanism for angular momentum transport in accretion disks. We present global, three dimensional (3D), MHD accretion disk simulations that investigate the dependence of the turbulent stresses…

High Energy Astrophysical Phenomena · Physics 2015-06-16 E. R. Parkin , G. V. Bicknell

We use a global magnetohydrodynamic simulation of a geometrically thin accretion disk to investigate the locality and detailed structure of turbulence driven by the magnetorotational instability (MRI). The model disk has an aspect ratio $H…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Kris Beckwith , Philip J. Armitage , Jacob B. Simon

We characterize magnetically driven accretion at radii between 1 au and 100 au in protoplanetary discs, using a series of local non-ideal magnetohydrodynamic (MHD) simulations. The simulations assume a Minimum Mass Solar Nebula (MMSN) disc…

Solar and Stellar Astrophysics · Physics 2015-10-07 Jacob B. Simon , Geoffroy Lesur , Matthew W. Kunz , Philip J. Armitage

Discretized numerical simulations are a powerful tool for investigation of nonlinear MHD turbulence in accretion disks. However, confidence in their quantitative predictions requires a demonstration that further refinement of the spatial…

High Energy Astrophysical Phenomena · Physics 2015-05-27 John F. Hawley , Xiaoyue Guan , Julian H. Krolik

We investigate numerical convergence in simulations of magnetically arrested disks around spinning black holes. Using the general-relativistic magnetohydrodynamics code Athena++, we study the same system at four resolutions (up to an…

High Energy Astrophysical Phenomena · Physics 2019-06-25 Christopher J. White , James M. Stone , Eliot Quataert

Global disk simulations provide a powerful tool for investigating accretion and the underlying magnetohydrodynamic turbulence driven by the magneto-rotational instability (MRI). Using them to predict accurately quantities such as stress,…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 John F. Hawley , Sherwood A. Richers , Xiaoyue Guan , Julian H. Krolik

We use local numerical simulations to investigate the strength and nature of magnetohydrodynamic (MHD) turbulence in the outer regions of protoplanetary disks, where ambipolar diffusion is the dominant non-ideal MHD effect. The simulations…

Solar and Stellar Astrophysics · Physics 2015-06-11 Jacob B. Simon , Xue-Ning Bai , James M. Stone , Philip J. Armitage , Kris Beckwith

We present a detailed study of localised magnetohydrodynamical (MHD) instabilities occuring in two--dimensional magnetized accretion disks. We model axisymmetric MHD disk tori, and solve the equations governing a two--dimensional magnetized…

Astrophysics · Physics 2011-07-08 J. W. S. Blokland , R. Keppens , J. P. Goedbloed

The global development of magnetohydrodynamic turbulence in an accretion disk is studied within a simplified disk model that omits vertical stratification. Starting with a weak vertical seed field, a saturated state is obtained after a few…

Astrophysics · Physics 2009-10-30 Philip J. Armitage

We investigate the effect of shear viscosity and Ohmic resistivity on the magnetorotational instability (MRI) in vertically stratified accretion disks through a series of local simulations with the Athena code. First, we use a series of…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Jacob B. Simon , John F. Hawley , Kris Beckwith

Magnetic field fluctuations in MHD turbulence can be viewed as current sheets that are progressively more anisotropic at smaller scales. As suggested by Loureiro & Boldyrev (2017) and Mallet et al (2017), below a certain critical thickness…

Plasma Physics · Physics 2017-08-09 Stanislav Boldyrev , Nuno F. Loureiro

Global three dimensional magnetohydrodynamic (MHD) simulations of turbulent accretion disks are presented which start from fully equilibrium initial conditions in which the magnetic forces are accounted for and the induction equation is…

High Energy Astrophysical Phenomena · Physics 2015-06-12 E. R. Parkin , G. V. Bicknell

We present full 2 Pi global 3-D stratified MHD simulations of accretion disks. We interpret our results in the context of proto-planetary disks. We investigate the turbulence driven by the magneto-rotational instability (MRI) using the…

Earth and Planetary Astrophysics · Physics 2015-05-27 M. Flock , N. Dzyurkevich , H. Klahr , N. J. Turner , Th. Henning

We perform numerical simulations of magneto-rotational instability in a local patch of accretion disk in which radiation pressure exceeds gas pressure. Such conditions may occur in the central regions of disks surrounding compact objects in…

Astrophysics · Physics 2007-05-23 N. J. Turner , J. M. Stone , T. Sano

We numerically evolve turbulence driven by the magnetorotational instability (MRI) in a 3D, unstratified shearing box and study its structure using two-point correlation functions. We confirm Fromang and Papaloizou's result that shearing…

Astrophysics of Galaxies · Physics 2011-02-11 Xiaoyue Guan , Charles F. Gammie , Jacob B. Simon , Bryan M. Johnson

We present numerical simulations and explore scalings and anisotropy of compressible magnetohydrodynamic (MHD) turbulence. Our study covers both gas pressure dominated (high beta) and magnetically dominated (low beta) plasmas at different…

Astrophysics · Physics 2011-05-05 Jungyeon Cho , A. Lazarian
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