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Related papers: Self-Similar Solutions for ADAF with Toroidal Magn…

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We present new thermal equilibrium solutions for optically thin and thick disks incorporating magnetic fields. The purpose of this paper is to explain the bright hard state and the bright/slow transition observed in the rising phases of…

High Energy Astrophysical Phenomena · Physics 2010-01-15 H. Oda , M. Machida , K. E. Nakamura , R. Matsumoto

This paper considers gravitational perturbations in geometrically thin disks with rotation curves dominated by a central object, but with substantial contributions from magnetic pressure and tension. The treatment is general, but the…

Astrophysics of Galaxies · Physics 2015-05-20 Susana Lizano , Daniele Galli , Mike J. Cai , Fred C. Adams

We perform local, vertically stratified shearing-box MHD simulations of protoplanetary disks (PPDs) at a fiducial radius of 1 AU that take into account the effects of both Ohmic resistivity and ambipolar diffusion (AD). The magnetic…

Earth and Planetary Astrophysics · Physics 2015-06-12 Xue-Ning Bai , James M. Stone

We perform a linear analysis of the stability of isothermal, rotating, magnetic, self-gravitating sheets that are weakly ionized. The magnetic field and rotation axis are perpendicular to the sheet. We include a self-consistent treatment of…

Solar and Stellar Astrophysics · Physics 2021-05-17 Indrani Das , Shantanu Basu

The structure and magnitude of the electric field created by a rotating accretion disk with a poloidal magnetic field is found for the case of a vacuum approximation along the axis. The accretion disk is modeled as a torus filled with…

Astrophysics · Physics 2009-11-07 A. A. Shatskiy , N. S. Kardashev

Accretion disks in Active Galactic Nuclei (AGN) are predicted to become gravitationally unstable substantially interior to the black hole's sphere of influence, at radii where the disk is simultaneously unstable to the magnetorotational…

High Energy Astrophysical Phenomena · Physics 2025-07-30 Tsun Hin Navin Tsung , Mitchell C. Begelman , Philip J. Armitage , Yan-Fei Jiang , Hannalore J. Gerling-Dunsmore

Activity of the nuclei of galaxies and stellar mass systems involving disk accretion to black holes is thought to be due to (1) a small-scale turbulent magnetic field in the disk (due to the magneto-rotational instability or MRI) which…

High Energy Astrophysical Phenomena · Physics 2009-08-05 R. V. E. Lovelace , D. M. Rothstein , G. S. Bisnovatyi-Kogan

We analytically derive self-similar solutions for a time-dependent, one-dimensional, magnetically driven accretion-disk-wind model based on the magnetohydrodynamic equations. The model assumes a geometrically thin, gas-pressure-dominated…

High Energy Astrophysical Phenomena · Physics 2025-07-18 Mageshwaran Tamilan , Kimitake Hayasaki , Takeru K. Suzuki

Stars are self-gravitating fluids in which pressure, buoyancy, rotation and magnetic fields provide the restoring forces for global modes of oscillation. Pressure and buoyancy energetically dominate, while rotation and magnetism are…

Solar and Stellar Astrophysics · Physics 2017-04-19 Shyeh Tjing Loi , John C. B. Papaloizou

Radial transport of particles, elements and fluid driven by internal stresses in three-dimensional (3D) astrophysical accretion disks is an important phenomenon, potentially relevant for the outward dust transport in protoplanetary disks,…

High Energy Astrophysical Phenomena · Physics 2017-03-15 Alexander A. Philippov , Roman R. Rafikov

Stars and gaseous planets are magnetised objects but the influence of magnetic fields on their tidal responses and dissipation rates has not been well explored. We present the first exploratory nonlinear magnetohydrodynamic (MHD)…

Solar and Stellar Astrophysics · Physics 2024-11-26 Aurélie Astoul , Adrian J. Barker

The steady-state structure of self-gravitating, magnetized accretion disks is studied using a set of self-similar solutions which are appropriate in the outer regions. The disk is assumed to be isothermal and the magnetic field outside of…

Astrophysics · Physics 2009-11-13 Mohsen Shadmehri , Fazeleh Khajenabi

We obtained self-similar solutions of relativistically expanding magnetic loops taking into account the azimuthal magnetic fields. We neglect stellar rotation and assume axisymmetry and a purely radial flow. As the magnetic loops expand,…

Astrophysics · Physics 2009-11-13 Hiroyuki R. Takahashi , Eiji Asano , Ryoji Matsumoto

We propose that the strength of angular momentum transport in accretion discs threaded by net vertical magnetic field is determined by a self-regulation mechanism: the magnetorotational instability (MRI) grows until its own turbulent…

High Energy Astrophysical Phenomena · Physics 2023-04-18 Mitchell C. Begelman , Philip J. Armitage

We considered the effects of convection on the radiatively inefficient accretion flows (RIAF) in the presence of resistivity and toroidal magnetic field. We discussed the effects of convection on transports of angular momentum and energy.…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Kazem Faghei , Mobina Omidvand

For over 30 years, the Magneto-Rotational Instability has been accepted as the mechanism driving accretion disk turbulence. Its physical basis is well understood, where an interplay between centrifugal forces and magnetic tension transfers…

Astrophysics of Galaxies · Physics 2025-07-31 Nicolas Brughmans , Rony Keppens

Large scale magnetic field threading an accretion disk is a key ingredient in the jet formation model. The most attractive scenario for the origin of such a large scale field is the advection of the field by the gas in the accretion disk…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Xinwu Cao , H. C. Spruit

The secular variation of the geomagnetic field suggests that there are anticyclonic polar vortices in the Earth's core. Under the influence of a magnetic field, the polar azimuthal flow is thought to be produced by one or more coherent…

Geophysics · Physics 2023-10-11 Debarshi Majumder , Binod Sreenivasan

We have performed 3-D numerical magnetohydrodynamic (MHD) jet experiments to study the instabilities associated with strongly toroidal magnetic fields and determine if such magnetic configurations in jets are as unstable as similar…

Astrophysics · Physics 2007-05-23 F. Thomsen , A. Nordlund

We consider a self-similar force-free wind flowing out of an infinitely thin disk located in the equatorial plane. On the disk plane, we assume that the magnetic stream function $P$ scales as $P\propto R^\nu$, where $R$ is the cylindrical…

Astrophysics · Physics 2008-11-26 Ramesh Narayan , Jonathan C. McKinney , Alison J. Farmer