Non-LTE Models and Theoretical Spectra of Accretion Disks in Active Galactic Nuclei

We present self-consistent models of the vertical structure and emergentspectrum of AGN accretion disks. The central object is assumed to be asupermassive Kerr black hole. We demonstrate that NLTE effects and the effectsof a self-consistent vertical structure of a disk play a very important role indetermining the emergent radiation, and therefore should be taken into account.In particular, NLTE models exhibit a largely diminished H I Lyman discontinuitywhen compared to LTE models, and the He II discontinuity appears strongly inemission for NLTE models. Consequently, the number of ionizing photons in theHe II Lyman continuum predicted by NLTE disk models is by 1 - 2 orders ofmagnitude higher than that following from the black-body approximation. Thisprediction has important implications for ionization models of AGN broad lineregions, and for models of the intergalactic radiation field and the ionizationof helium in the intergalactic medium.Comment: 11 pages; 2 postscript figures; LaTeX, AASPP4 macro; to appear in the Astrophysical Journal (Letters