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Related papers: Steady-State Solutions for a Geometrically Thin Ac…

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Accretion flows may produce profuse winds when they have positive specific energy. Winds deplete matter from the inner region of the disk and makes the inner region thinner, optically. Since there are fewer electrons in this region, it…

Astrophysics · Physics 2007-05-23 Sandip K. Chakrabarti

We analyze a 900-ks stacked Chandra/HETG spectrum of NGC 3783 in the context of magnetically-driven accretion-disk wind models in an effort to provide tight constraints on the global conditions of the underlying absorbers. Motivated by the…

High Energy Astrophysical Phenomena · Physics 2018-02-07 Keigo Fukumura , Demosthenes Kazanas , Chris Shrader , Ehud Behar , Francesco Tombesi , Ioannis Contopoulos

We present the results of time-dependent hydrodynamic calculations of line- driven winds from accretion disks in AGN. To calculate the radiation force, we take into account radiation from the disk and the central engine. The gas temperature…

Astrophysics · Physics 2009-09-25 D. Proga , J. M. Stone , T. R. Kallman

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

An analytic model is proposed for non-radiating accretion flows accompanied by up or down winds in a global magnetic field. Physical quantities in this model solution are written in variable-separated forms, and their radial parts are…

Astrophysics · Physics 2009-11-07 Osamu Kaburaki

Mass transfer from an evolved donor star to its binary companion is a standard feature of stellar evolution in binaries. In wide binaries, the companion star captures some of the mass ejected in a wind by the primary star. The captured…

Solar and Stellar Astrophysics · Physics 2015-06-04 Hagai B. Perets , Scott J. Kenyon

By performing local three-dimensional MHD simulations of stratified accretion disks, we investigate disk winds driven by MHD turbulence. Initially given weak vertical magnetic fields are effectively amplified by magnetorotational…

Astrophysics · Physics 2015-05-13 T. K. Suzuki , S. Inutsuka

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

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

A toy model of a disk undergoing steady state accretion onto a black hole is presented. The disk is in a hydrostatic equilibrium for all radii r > r_{in}, with the inner disk radius located between the marginally stable and marginally bound…

Astrophysics · Physics 2007-05-23 Bohdan Paczynski

We compare the stellar wind torque calculated in a previous work (Paper II) to the spin-up and spin-down torques expected to arise from the magnetic interaction between a slowly rotating ($\sim 10$% of breakup) pre-main-sequence star and…

Astrophysics · Physics 2009-11-13 Sean Matt , Ralph E. Pudritz

Many analyses have concluded that the accretion disc sizes measured from the microlensing variability of quasars are larger than the expectations from the standard thin disc theory by a factor of $\sim4$. We propose a simply model by…

High Energy Astrophysical Phenomena · Physics 2018-12-05 Ya-Ping Li , Feng Yuan , Xinyu Dai

We present global solutions of optically thin, two-temperature black hole accretion disks incorporating magnetic fields. We assume that the {\pi}{\phi}-component of the Maxwell stress is proportional to the total pressure, and prescribe the…

High Energy Astrophysical Phenomena · Physics 2015-05-30 Hiroshi Oda , Mami Machida , Kenji E. Nakamura , Ryoji Matsumoto , Ramesh Narayan

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

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

Over two hundred protoplanetary disk systems have been resolved by ALMA, and the vast majority suggest the presence of planets. The dust gaps in transition disks are considered evidence of giant planets sculpting gas and dust under…

Earth and Planetary Astrophysics · Physics 2024-06-05 Yinhao Wu

A new type of wind - a conical wind - has been discovered in axisymmetric magnetohydrodynamic simulations of the disk-magnetosphere interaction in cases where the magnetic field of the star is bunched into an X-type configuration. Such a…

Solar and Stellar Astrophysics · Physics 2009-01-28 M. M. Romanova , G. V. Ustyugova , A. V. Koldoba , R. V. E. Lovelace

A simple 1D dynamical model of thermally driven disc winds is proposed, based on the results of recent, 2.5D axi-symmetric simulations. Our formulation of the disc wind problem is in the spirit of the original Parker (1958) and Bondi (1952)…

Solar and Stellar Astrophysics · Physics 2015-06-05 Timothy R. Waters , Daniel Proga

This paper studies the response of a thin accretion disk to an external radial magnetic field. Our focus is on protoplanetary disks (PPDs), which are exposed during their later evolution to an intense, magnetized wind from the central star.…

Earth and Planetary Astrophysics · Physics 2015-11-04 Matthew Russo , Christopher Thompson

Based on the characteristics of the magnetorotational instability (MRI) and the MRI-driven turbulence, we construct a steady model for a geometrically thin disk using "non-standard" $\alpha$-prescription. The efficiency of the angular…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Hiroyuki R. Takahashi , Youhei Masada