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Cold steady-state disk wind theory from near Keplerian accretion disks requires a large scale magnetic field at near equipartition strength. However the minimum magnetization has never been tested. We investigate the time evolution of an…

Solar and Stellar Astrophysics · Physics 2015-03-13 Gareth C. Murphy , Jonathan Ferreira , Claudio Zanni

We use global magnetohydrodynamic simulations to study the influence of net vertical magnetic fields on the structure of geometrically thin ($H/r \approx 0.05$) accretion disks in the Newtonian limit. We consider initial mid-plane gas to…

High Energy Astrophysical Phenomena · Physics 2020-01-23 Bhupendra Mishra , Mitchell C. Begelman , Philip J. Armitage , Jacob B. Simon

Aims: We investigate the evolution of protoplanetary discs (PPDs hereafter) with magnetically driven disc winds and viscous heating. Methods: We consider an initially massive disc with ~0.1 Msun to track the evolution from the early stage…

Earth and Planetary Astrophysics · Physics 2016-12-07 Takeru K. Suzuki , Masahiro Ogihara , Alessandro Morbidelli , Aurélien Crida , Tristan Guillot

The evolution of protoplanetary discs and the related process of planet formation is regulated by angular momentum transport and mass-loss processes. Over the past decade, the paradigm of viscosity has been challenged and MHD disc winds…

Solar and Stellar Astrophysics · Physics 2021-12-08 Benoît Tabone , Giovanni P. Rosotti , Alexander J. Cridland , Philip J. Armitage , Giuseppe Lodato

The existence of outflow in accretion flows is confirmed by observations and magnetohydrodynamics (MHD) simulations. In this paper, we study outflows of accretion flows in the presence of resistivity and toroidal magnetic field. The…

High Energy Astrophysical Phenomena · Physics 2012-05-11 Kazem Faghei , Azam Mollatayefeh

We study the steady-state structure of an accretion disc with a corona surrounding a central, rotating, magnetized star. We assume that the magneto-rotational instability is the dominant mechanism of angular momentum transport inside the…

Astrophysics · Physics 2009-06-23 Fazeleh Khajenabi , Mohsen Shadmehri , Sami Dib

The traditional paradigm of viscosity-dominated evolution of protoplanetary discs has been recently challenged by magnetized disc winds. However, distinguishing wind-driven and turbulence-driven accretion through observations has been…

Earth and Planetary Astrophysics · Physics 2023-05-30 Yinhao Wu , Yi-Xian Chen , Haochang Jiang , Ruobing Dong , Enrique Macías , Min-Kai Lin , Giovanni P. Rosotti , Vardan Elbakyan

We present a study of X-ray ionization of magnetohydrodynamic (MHD) accretion-disk winds in an effort to constrain the physics underlying the highly-ionized ultra-fast outflows (UFOs) inferred by X-ray absorbers often detected in various…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Keigo Fukumura , Francesco Tombesi , Demosthenes Kazanas , Chris Shrader , Ehud Behar , Ioannis Contopoulos

We present steady-state solutions for a one-dimensional, magnetically-driven accretion disk wind model based on magnetohydrodynamic equations. We assume a geometrically thin, gas-pressure-dominated accretion disk, incorporating both…

High Energy Astrophysical Phenomena · Physics 2025-01-23 Mageshwaran Tamilan , Kimitake Hayasaki , Takeru K. Suzuki

We studied magnetically arrested disks (MAD) around rotating black holes (BH), under the influence of radiative cooling. We introduce a critical value of the mass accretion rate $\dot M_{\rm crit}$ for which the cooling by the synchrotron…

High Energy Astrophysical Phenomena · Physics 2025-02-18 Akshay Singh , Damien Bégué , Asaf Pe'er

We study an accretion disc with a hot continuous corona. We assume that the corona itself accretes and therefore it is powered directly by the release of the gravitational energy and cooled by radiative interaction with the disc. We…

Astrophysics · Physics 2015-06-24 H. J. Witt , B. Czerny , P. T. Zycki

We present a systematic, analytical study of geometrically thin, optically thick accretion disc solutions for magnetized turbulent flows, with an alpha-like viscosity prescription. Under the only assumptions that (1) Magneto-Rotational…

Astrophysics · Physics 2009-11-07 A. Merloni

X-ray observations of the tidal disruption event (TDE) candidate AT 2019avd show drastic variabilities in flux and spectral shape over hundreds of days, providing clues on the accretion disc-corona evolution. We utilize a disc-corona model,…

High Energy Astrophysical Phenomena · Physics 2026-03-27 Haichao Xu , Xinwu Cao , Yanan Wang , Andrzej A. Zdziarski

We review some recent results of general relativistic magnetohydrodynamic (GR-MHD) simulations considering the evolution of geometrically thin disks around a central black hole. Thin disk GR-MHD simulations complement the widely used MAD…

High Energy Astrophysical Phenomena · Physics 2024-04-10 Indu K. Dihingia , Christian Fendt

We investigate under which conditions cold, fan-shaped winds can be steadily launched from thin (Keplerian) accretion discs. Such winds are magneto-centrifugal winds launched from a thin annulus in the disc, along open magnetic field lines…

Solar and Stellar Astrophysics · Physics 2015-06-11 Jonathan Ferreira , Fabien Casse

We study the local thermal stability of thin accretion disks. We present a full stability analysis in the presence of a magnetic field and more importantly wind. For wind, we use a general model suitable for adequately describing several…

Astrophysics of Galaxies · Physics 2020-01-08 Asiyeh Habibi , Shahram Abbassi

Protoplanetary discs (PPDs) are cold, dense and weakly ionised environments that witness the planetary formation. Among these discs, transition discs (TDs) are characterised by a wide cavity in the dust and gas distribution. Despite this…

Earth and Planetary Astrophysics · Physics 2022-11-02 Étienne Martel , Geoffroy Lesur

We present the first-ever simulations of non-ideal magnetohydrodynamical (MHD) stellar magnetospheric winds coupled with disc-driven jets where the resistive and viscous accretion disc is self-consistently described. These innovative MHD…

Astrophysics · Physics 2011-02-19 Z. Meliani , F. Casse , C. Sauty

We present Green's function solutions for a geometrically thin, one-dimensional Keplerian accretion disk that includes angular momentum extraction and mass loss due to magnetohydrodynamic (MHD) winds. The disk viscosity is assumed to vary…

High Energy Astrophysical Phenomena · Physics 2026-01-01 Mageshwaran Tamilan

We present a model for a super-Eddington accretion disc around a magnetized neutron star taking into account advection of heat and the mass loss by the wind. The model is semi-analytical and predicts radial profiles of all basic physical…

High Energy Astrophysical Phenomena · Physics 2019-06-05 Anna Chashkina , Galina Lipunova , Pavel Abolmasov , Juri Poutanen