C136 ブラックホール近傍降着円盤の構造と進化
スポンサーリンク
概要
- 論文の詳細を見る
The dynamical evolution of accreting flow onto a black hole has been investigated using a general-relativistic, hydrodynamic code which contains a viscosity based on the α-model. There are three types of flow's pattern which correspond to the thickness of the accretion disk. In a case of the thin disk with a thickness less than the radius of the event horizon at the vicinity of a marginally stable orbit, the accreting flow through a surface of the marginally stable orbit becomes thinner due to a additional cooling caused by a general-relativistic Roche-lobe overflow and horizontal advection of heat. An accretion disk with a middle thickness, (2r)_h<h<(3r)_h, divides into two flows : the upper region of the accreting flow expands into the atmosphere of the black hole, and the inner region of the flow becomes thinner, smoothly accreting onto the black hole. The expansion of the flow generates a dynamically violent structure around the event horizon. The kinetic energy of the violent motion becomes equivalent to the thermal energy of the accreting disk. The shock heating due to violent motion produces a thermally driven wind which flows through the atmosphere above the accretion disk. A very thick disk, (4r)_h<h, forms a shock front near to the mid-plane of the accreting flow. The accretion flowing through the thick disk, (2r)_h<h, cannot only form a single, laminar flow falling into the black hole, but also produces turbulent-like structure above the event horizon. The thick disk may possibly emit the X-ray and γ-ray radiation observed in active galactic nuclei.
- 日本流体力学会の論文
- 2001-07-31