English
Related papers

Related papers: Magnetic pressure support and accretion disk spect…

200 papers

It is established that the formation of rotationally supported disks during the main accretion phase of star formation is suppressed by a moderately strong magnetic field in the ideal MHD limit. Non-ideal MHD effects are expected to weaken…

Astrophysics · Physics 2011-02-11 Richard R. Mellon , Zhi-Yun Li

Magnetohydrodynamic accretion disk simulations suggest that much of the energy liberated by the magnetorotational instability (MRI) can be channeled into large-scale toroidal magnetic fields through dynamo action. Under certain conditions,…

High Energy Astrophysical Phenomena · Physics 2015-08-19 Mitchell C. Begelman , Philip J. Armitage , Christopher S. Reynolds

Accretion discs properties should deviate from standard theory when magnetic pressure exceeds the thermal pressure. To quantify these deviations, we present a systematic study of the dynamical properties of magnetically arrested discs…

High Energy Astrophysical Phenomena · Physics 2023-10-26 Nicolas Scepi , Mitchell C. Begelman , Jason Dexter

Magnetic effects have long been considered a possible factor in stabilizing the outer regions of active galactic nuclei (AGN) accretion disks against gravitational instability (GI). However, the computational demands of testing this…

High Energy Astrophysical Phenomena · Physics 2025-08-26 Hannalore J. Gerling-Dunsmore , Mitchell C. Begelman , Jacob B. Simon , Philip J. Armitage

We present a general linear dispersion relation which describes the coupled behavior of magnetorotational, photon bubble, and convective instabilities in weakly magnetized, differentially rotating accretion disks. We presume the accretion…

Astrophysics · Physics 2009-10-31 Omer Blaes , Aristotle Socrates

We investigate the dynamics of the accretion disks of young stars with fossil large-scale magnetic field. The author's magnetohydrodynamic (MHD) model of the accretion disks is generalized to consider the dynamical influence of the magnetic…

Solar and Stellar Astrophysics · Physics 2022-12-28 Sergey A. Khaibrakhmanov , Alexander E. Dudorov

(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

We extend our analysis of the three-dimensional response of a vertically polytropic disk to tidal forcing at Lindblad resonances by including the effects of a disk atmosphere. The atmosphere is modeled as an isothermal layer that joins…

Astrophysics · Physics 2009-10-30 G. I. Ogilvie , S. H. Lubow

We review the current status of studies on accretion and protoplanetary disks of young stars with large-scale magnetic fields. Observational data on magnetic fields of the disks are compiled and analysed. Modern analytical and numerical MHD…

Solar and Stellar Astrophysics · Physics 2024-01-26 Sergey A. Khaibrakhmanov

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

The results of three-dimensional MHD numerical simulations are used to investigate the characteristic properties of the magnetic-field structures in the accretion disks of semi-detached binary systems. It is assumed that the intrinsic…

Solar and Stellar Astrophysics · Physics 2010-07-21 A. G. Zhilkin , D. V. Bisikalo

A selection of results from the general relativistic MHD accretion simulations described in the previous talk are presented. We find that the magnetic field strength increases sharply with decreasing radius and is also enhanced near…

Astrophysics · Physics 2008-11-26 J. H. Krolik , S. Hirose

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 supplement the analytic solution obtained by Matthews O. M., et. al., 2005, MNRAS, \textbf{356}, 66 to investigate the steady-state structure of radiation pressure dominated disc under the influence of a stellar magnetic field which…

General Relativity and Quantum Cosmology · Physics 2020-05-26 Snehasish Bhattacharjee

We consider the accretion process in a disk with magnetic fields that are dragged in from the interstellar medium by gravitational collapse. Two diffusive processes are at work in the system: (1) "viscous" torques exerted by turbulent and…

We present global magnetohydrodynamic (MHD) simulations of accretion disks with a strong toroidal magnetic field using an equation of state that fixes the gas thermal scale height. The disk forms from the inflow of a rotating magnetized gas…

High Energy Astrophysical Phenomena · Physics 2025-05-20 Minghao Guo , Eliot Quataert , Jonathan Squire , Philip F. Hopkins , James M. Stone

In this paper we report on the formation of magnetically-levitating accretion disks around supermassive black holes. The structure of these disks is calculated by numerically modelling tidal disruption of magnetized interstellar gas clouds.…

Astrophysics of Galaxies · Physics 2015-06-03 Evghenii Gaburov , Anders Johansen , Yuri Levin

Multiple models have been suggested over the years to explain the structure and support of accretion disks around supermassive black holes, from the standard thin thermal-pressure-dominated $\alpha$-disk model to more recent models that…

High Energy Astrophysical Phenomena · Physics 2026-04-28 Yashvardhan Tomar , Philip F. Hopkins , Kyle Kremer

We theoretically investigate the magnetic flux transport in geometrically thick accretion discs which may form around black holes. We utilize a two-dimensional (2D) kinematic mean-field model for poloidal field transport which is governed…

High Energy Astrophysical Phenomena · Physics 2023-10-02 Ryoya Yamamoto , Shinsuke Takasao

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