On a discontinuity at the base of the transition layer located between the Keplerian accretion disk and the compact object

We study the geometry of the transition layer (TL) between the classical Keplerian accretion disk (the TL outer boundary) and the compact object at the TL inner boundary. Our goal is to demonstrate using the hydrodynamical formalism that the TL is created along with a shock due to a discontinuity and to an adjustment of the Keplerian disk motion to a central object. We apply hydrodynamical equations to describe a plasma motion near a central object in the TL. We point out that before matter accretes to a central object the TL cloud is formed between an adjustment radius and the TL inner boundary which is probably a site where the emergent Compton spectrum comes from. Using a generalization of the Randkine-Hugoniot relation and a solution of the azimutal force balance equation we have reproduced the geometric characteristics of TL.