Models of high-luminosity accretion disks surrounding black holes

Abstract: The problem of steady-state accretion to nonrotating black holes is examined. Advection is included and generalized formulas for the radiation pressure in both the optically thick and thin cases are used. Special attention is devoted to models with a high accretion rate. Global solutions for accretion disks are studied which describe a continuous transition between an optically thick outer region and an optically thin inner region. It is shown that there is a maximum disk temperature for the model with a viscosity parameter {\alpha} = 0.5. For the model with {\alpha} = 0.1, no optically thin regions are found to exist for any accretion rate.