Non-LTE models and theoretical spectra of accretion disks in Active Galactic Nuclei

Abstract

We present self-consistent models of the vertical structure and emergent spectrum of AGN accretion disks. The central object is assumed to be a supermassive Kerr black hole. We demonstrate that non-LTE effects and the effects of a self-consistent vertical structure of a disk play a very important role in determining the emergent radiation, and therefore should be taken into account. In particular, non-LTE models exhibit a largely diminished H I Lyman discontinuity, and strong emission in the He II Lyman discontinuity. Consequently, the number of ionizing photons in the He II Lyman continuum predicted by non-LTE disk models is by 1–2 orders of magnitude higher than that following from the black-body approximation. We have also shown that metal line opacities are very important in predicting emergent spectra from AGN disks.