Effects of Inner Torque and Dissipation Profiles on the Spectra and Structure of Accretion Disks

We present numerical spectral and vertical structure calculations appropriate for near-Eddington luminosity, radiation pressure dominated accretion disks around stellar mass black holes. We cover a wide range of black hole spins, and incorporate several dissipation profiles based on first-principles three-dimensional MHD disk interior simulations. We also include non-zero stresses at the ISCO, which results in the disk effective temperature to increase rapidly towards the black hole, and give rise to rather extreme conditions with high temperatures and low surface densities. We found that the combined effects of torque at the inner edge and increased dissipation near the photosphere led to energetically significant hard spectral tails extending to beyond a hundred keV. We discuss the implications of our results in the context of the steep power law (SPL) state and the associated high-frequency quasi-periodic oscillations (HFQPO) observed in some X-ray binary systems.