When the accretion rate is sub-Eddington and the opacity very high, the standard thin accretion disk is formed. It is geometrically thin in the vertical direction (has a disk-like shape), and is made of a relatively cold gas, with a negligible radiation pressure.

In this series of lectures, presented is a numerical simulations setup for a quasi-stationary thin magnetic accretion disk, based on the analytical solution. I detail the setup in both Newtonian and in General Rela-tivistic codes. Lectures about the Newtonian part of the setup were delivered at the Silesian University in Opava in

The Novikov-Thorne model describes geometrically thin and optically thick accre- tion disks around black holes. Accretion is possible because viscous magnetic or

of the accretion disk will have an opacity dominated by electron scattering. The boundary layer emits half the accretion luminosity. In the absence of a magnetic field, the accretion disk can extend all the way to the surface of the compact object, and the boundary layer consists of a very thin region just above the surface of the compact object.

Within a thin disk approximation some quantities are functions of radius only: j(r), Ω(r), e(r), while others are function of radius and time: Σ(r, t), M(r, ̇ t), ̇J(r, t), ̇E(r, t), F(r, t), g(r, t). Taking this into account the equations (d1.15), (d1.16), (d1.17) may be transformed into. ̇ ∂ M +. ̇ dj.

In our initial study of disk accretion, we will make a couple of important simplifying assumptions. We will assume that the disk is axisymmetric, and that it is thin, with. scale height h ⌧ Rdisk, the radius of the disk. where R and z are the radial and vertical coordinates in our cylindrical coordinate system.

2017年6月2日 · The chapter reviews the Novikov-Thorne model, which is the standard framework for geometrically thin and optically thick accretion disks around black holes, pointing out its assumptions. It also describes the transfer function for thin accretion disks and how the...

from the accretion disk. We will therefore take a closer look at accretion disks. One model of disks, which has many advantages (e.g., it is robust and does not depend on too many parameters) is one in which the disks are geometrically thin but optically thick. Let’s think about the conditions for this to occur.

The chapter reviews the Novikov-Thorne model, which is the standard framework for geometrically thin and optically thick accretion disks around black holes, pointing out its assumptions. It also describes the transfer function for thin accretion disks and how the transfer function can be calculated in a stationary and axisymmetric spacetime and ...

Non-standard model –ADAF is an optically thin geometry thick model and cooled by free-free emission which is not efficient comparing to the blackbody radiation. We use a self-similar solution...