The spectra of accretion discs in active galactic nuclei

Abstract

Fully self-consistent calculations of the spectra emitted by accretion discs in active galactic nuclei are presented. The inner, radiation-pressure-dominated regions of standard α-discs are treated. Incoherent Compton scattering and emission/absorption of radiation by hydrogen and helium are included in computing the vertical temperature structure within the disc and the emergent spectrum. Comptonization modifies the EUV/soft X-ray continuum and the He II spectral features. In particular, an important fraction of the emergent luminosity appears in the form of a steep soft X-ray spectrum