Dynamical Structure of Viscous Accretion Disks with Shocks

We develop and discuss global accretion solutions for viscous ADAF disks containing centrifugally supported isothermal shock waves. The fact that such shocks can exist at all in ADAF disks is a new result. Interestingly, we find that isothermal shocks can form even when the level of viscous dissipation is relatively high. In order to better understand this phenomenon, we explore all possible combinations of the fundamental flow parameters, such as specific energy, specific angular momentum, and viscosity, to obtain the complete family of global solutions. This procedure allows us to identify the region of the parameter space where isothermal shocks can exist in viscous ADAF disks. The allowed region is maximized in the inviscid case, and it shrinks as the level of viscous dissipation increases. Adopting the canonical value γ = 1.5 for the ratio of specific heats, we find that the shock region disappears completely when the Shakura-Sunyaev Also at: Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030-4444, USA.