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Related papers: Wind-driving protostellar accretion discs. II. Num…

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Using the anelastic approximation of linearised hydrodynamic equations, we investigate the development of axially symmetric small perturbations in thin Keplerian discs. The sixth-order dispersion equation is derived and numerically solved…

High Energy Astrophysical Phenomena · Physics 2015-07-02 N. Shakura , K. Postnov

We carry out a series of local, vertically stratified shearing box simulations of protoplanetary disks that include ambipolar diffusion and a net vertical magnetic field. The ambipolar diffusion profiles we employ correspond to 30AU and…

Solar and Stellar Astrophysics · Physics 2015-06-16 Jacob B. Simon , Xue-Ning Bai , Philip J. Armitage , James M. Stone , Kris Beckwith

Understanding dispersal of protoplanetary disks remains a central challenge in planet formation theory. Disk winds, driven by magnetohydrodynamics (MHD) and/or photoevaporation, are now recognized as primary agents of dispersal. With the…

Earth and Planetary Astrophysics · Physics 2026-02-25 R. Nakatani , G. Rosotti , B. Tabone , A. Sellek

We explore the poloidal structure of two-dimensional (2D) MHD winds in relation to their potential association with the X-ray warm absorbers (WAs) and the highly-ionized ultra-fast outflows (UFOs) in AGN, in a single unifying approach. We…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Keigo Fukumura , Francesco Tombesi , Demosthenes Kazanas , Chris Shrader , Ehud Behar , Ioannis Contopoulos

We want to test if self-similar magneto-hydrodynamic (MHD) accretion-ejection models can explain the observational results for accretion disk winds in BHBs. In our models, the density at the base of the outflow, from the accretion disk, is…

High Energy Astrophysical Phenomena · Physics 2016-05-25 S. Chakravorty , P-O. Petrucci , J. Ferreira , G. Henri , R. Belmont , M. Clavel , S. Corbel , J. Rodriguez , M. Coriat , S. Drappeau , J. Malzac

We consider an extreme case of disc accretion onto a gravitating centre when the viscosity in the disc is negligible. The angular momentum and the rotational energy of the accreted matter is carried out by a magnetized wind outflowing from…

Astrophysics · Physics 2010-04-28 Sergei Bogovalov , Stanislav Kelner

This paper examines the outflows associated with the interaction of a stellar magnetosphere with an accretion disk. In particular, we investigate the magnetospheric ejections (MEs) due to the expansion and reconnection of the field lines…

Solar and Stellar Astrophysics · Physics 2015-06-12 Claudio Zanni , Jonathan Ferreira

We derive expressions for the local ideal magnetohydrodynamic (MHD) equations for a warped astrophysical disc using a warped shearing box formalism. A perturbation expansion of these equations to first order in the warping amplitude leads…

Solar and Stellar Astrophysics · Physics 2018-04-04 Joseph B. Paris , Gordon I. Ogilvie

In the early stages of star formation, boundary layer accretion, where protostars accrete material from disks extending down to their surfaces, plays a crucial role. Understanding how a magneto-rotational-instability (MRI)-active disk…

Solar and Stellar Astrophysics · Physics 2025-03-20 Shinsuke Takasao , Takashi Hosokawa , Kengo Tomida , Kazunari Iwasaki

Protoplanetary discs are poorly ionised due to their low temperatures and high column densities, and are therefore subject to three "non-ideal" magnetohydrodynamic effects: Ohmic dissipation, ambipolar diffusion, and the Hall effect. The…

Solar and Stellar Astrophysics · Physics 2014-07-02 Geoffroy Lesur , Matthew W. Kunz , Sebastien Fromang

The strength and structure of the large-scale magnetic field in protoplanetary discs are still unknown, although they could have important consequences for the dynamics and evolution of the disc. Using a mean-field approach in which we…

Earth and Planetary Astrophysics · Physics 2015-06-19 Jerome Guilet , Gordon I. Ogilvie

Magnetic fields likely play a key role in the dynamics and evolution of protoplanetary discs. They have the potential to efficiently transport angular momentum by MHD turbulence or via the magnetocentrifugal acceleration of outflows from…

Astrophysics · Physics 2009-06-23 Mark Wardle

MHD winds can emanate from both stars and surrounding accretion disks. It is of interest to know how much wind power is available and which (if either) of the two rotators dominates that power. We investigate this in the context of…

Astrophysics · Physics 2009-10-31 Eric G. Blackman , Adam Frank , Carl Welch

I review the main results from recent 2-D, time-dependent hydrodynamic models of radiation-driven winds from accretion disks in AGN. I also discuss the physical conditions needed for a disk wind to be shielded from the strong X-rays and to…

Astrophysics · Physics 2007-05-23 D. Proga

The vertical temperature structure of a protoplanetary disk bears on several processes relevant to planet formation, such as gas and dust grain chemistry, ice lines and convection. The temperature profile is controlled by irradiation from…

Earth and Planetary Astrophysics · Physics 2020-05-07 William Béthune , Henrik Latter

Winds from accretion disks have been proposed as the driving source for precessing jets and extreme bipolar morphologies in Planetary Nebulae (PNe) and proto-PNe (pPNe). Here we apply MHD disk wind models to PNe and pPNe by estimating…

Astrophysics · Physics 2007-05-23 Adam Frank

We study the evolution of magnetic fields in accretion flows around six different sink particles in a global star formation simulation. Using the adaptive mesh refinement capabilities of \ramses, the vicinity of the sinks is resolved with a…

Solar and Stellar Astrophysics · Physics 2017-11-01 Michael Kuffmeier , Farrukh Nauman

Describing the large-scale field topology of protoplanetary disks faces significant difficulties and uncertainties. The transport of the large-scale field inside the disk plays an important role in understanding its evolution. We aim to…

Solar and Stellar Astrophysics · Physics 2025-11-26 D. Steiner , L. Gehrig , M. Güdel

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 an analytical model to investigate the production of pebbles and their radial transport through a protoplanetary disk (PPD) with magnetically driven winds. While most of the previous analytical studies in this context assume that…

Earth and Planetary Astrophysics · Physics 2018-08-15 Mohsen Shadmehri , Fazeleh Khajenabi , Martin E. Pessah