Structure of Accretion Disks with Optically Thick--Optically Thin Transitions

Artemova, I. V.; Бисноватый-Коган, Г. С.; Bjoernsson, G.; Новиков, И. Д.

doi:10.1086/176632

Cited by 57 publications

(51 citation statements)

References 12 publications

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“…Using F 0 instead of Q − and equation of state P = ρRT + P rad,0 , the equations of accretion disk structure together with equation with Q + from (88), have been solved numerically by Artemova et al (1996). It occures that two solutions, optically thick and optically thin, exist separately when luminosity is not very large.…”

Section: 6mentioning

confidence: 99%

Advective accretion disks and related problems including magnetic fields

Бисноватый-Коган

Lovelace

2001

New Astronomy Reviews

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Accretion disk theory was first developed as a theory with the local heat balance, where the whole energy produced by a viscous heating was emitted to the sides of the disk. One of the most important new invention of this theory was the phenomenological treatment of the turbulent viscosity, known the " alpha" prescription, where the (rφ) component of the stress tensor was approximated by (αp) with a unknown constant α. This prescription played the role in the accretion disk theory as well important as the mixing-length theory of convection for stellar evolution. Sources of turbulence in the accretion disk are discussed, including hydrodynamical turbulence, convection and magnetic field role. In parallel to the optically thick geometrically thin accretion disk models, a new branch of the optically thin accretion disk models was discovered, with a larger thickness for the same total luminosity. The choice between these solutions should be done of the base of a stability analysis. The ideas underlying the necessity to include advection into the accretion disk theory are presented and first models with advection are reviewed. The present status of the solution for a low-luminous optically thin accretion disk model with advection is discussed and the limits for an advection dominated accretion flows (ADAF) imposed by the presence of magnetic field are analysed. Related problems of mass ejection from accretion disks and jet formation are discussed.

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Section: 6mentioning

confidence: 99%

Advective accretion disks and related problems including magnetic fields

Бисноватый-Коган

Lovelace

2001

New Astronomy Reviews

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“…The radiation transfer in the disk, on the other hand, has been investigated in relation to the structure of a static disk atmosphere and the spectral energy density from the disk surface (e.g., Meyer, Meyer-Hofmeister 1982;Cannizzo, Wheeler 1984;Shaviv, Wehrse 1986;Adam et al 1988;Hubeny 1990; Ross et al 1992; Artemova et al 1996;Hubeny, Hubeny 1997Hubeny et al 2000Hubeny et al , 2001Davis et al 2005;Hui et al 2005; see also Mineshige, Wood 1990). In these studies, however, the vertical movement and mass loss were not considered.…”

Section: Introductionmentioning

confidence: 99%

Radiative Flow in a Luminous Disk

Fukue

2005

Publications of the Astronomical Society of Japan

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Radiatively driven flow in a luminous disk is examined in the subrelativistic regime of (v/c) 1 , taking account of radiation transfer. The flow is assumed to be vertical, and the gravity and gas pressure are ignored. When internal heating is dropped, for a given optical depth and radiation pressure at the flow base (disk "inside"), where the flow speed is zero, the flow is analytically solved under the appropriate boundary condition at the flow top (disk "surface"), where the optical depth is zero. The loaded mass and terminal speed of the flow are both determined by the initial conditions; the mass-loss rate increases as the initial radiation pressure increases, while the flow terminal speed increases as the initial radiation pressure and the loaded mass decrease. In particular, when heating is ignored, the radiative flux F is constant and the radiation pressure P 0 at the flow base with optical depth τ 0 is bound in the range of 2/3 < cP 0 /F < 2/3 + τ 0 . In this case, at the limit of cP 0 /F = 2/3 + τ 0 , the loaded mass diverges and the flow terminal speed becomes zero, while, at the limit of cP 0 /F = 2/3, the loaded mass becomes zero and the terminal speed approaches (3/8) c, which is the terminal speed above the luminous flat disk under an approximation of the order of (v/c) 1 . We also examine the case where heating exists, and find that the flow properties are qualitatively similar to the case without heating.

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“…This system of equations is reduced to a single algebraic nonlinear equation for the sound speed c s (Artemova et al 1996) …”

Section: Time-delay Modelmentioning

confidence: 99%

Time delay between the optical and X-ray outbursts in the high-mass X-ray transient A0535+26/HDE245770

Giovannelli¹,

Бисноватый-Коган²,

Klepnev³

2013

A&A

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The optical behavior of the Be star in the high-mass X-ray transient A0535+26/HDE245770 shows that at periastron the luminosity is typically enhanced by 0.02 to a few tenths mag, and the X-ray outburst occurs eight days after the periastron. We constructed a quantitative model for this event based on a nonstationary accretion disk behavior, connected with a high ellipticity of the orbital motion. We explain the observed time delay between the peaks of the optical and X-ray outbursts in this system by the time of radial motion of the matter in the accretion disk, after an increase of the mass flux in the vicinity of a periastral point in the binary. This time is determined by the turbulent viscosity with a parameter of α = 0.1−0.3. The increase of the mass flux is a sort of flush that reaches the external part of the accretion disk around the neutron star, which enhances the optical luminosity. The subsequent X-ray flare occurs when the matter reaches the hot central parts of the accretion disk and the neutron star's surface.

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Structure of Accretion Disks with Optically Thick--Optically Thin Transitions

Cited by 57 publications

References 12 publications

Advective accretion disks and related problems including magnetic fields

Advective accretion disks and related problems including magnetic fields

Radiative Flow in a Luminous Disk

Time delay between the optical and X-ray outbursts in the high-mass X-ray transient A0535+26/HDE245770

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