Seong-Jae* Lee and Dongsu Ryu*
We studied the structure formed around a black hole as a consequence of
one-dimensional, quasi-spherical, supersonic accretion flows. The structure
accompanies an accretion shock, inside which the flow is subsonic and is
dissipated by viscosity. The dissipated energy is assumed to be mostly
stored as entropy rather than being radiated. We found that the viscous
angular momentum transfer should cause
∂l⁄∂r<0, close to the accretion shock. Here
l is the specific angular momentum and r is the distance from
black hole. Hence, the flow there is subject to rotational instability. The
rotational instability results in creating new shocks. We present the
unstable flow structure with the accretion shock induced by the rotational
instability.
*Department of Astronomy and Space Science, Chungnam National
University, Daejeon 305-764, S. Korea