POLARIZATION OF RADIATION FROM AGN ACCRETION DISKS

A popular candidate for the Blue Bump often seen in AGN spectra is thermal radiation from an accretion disk. In models for disks surrounding supermassive black holes, such radiation would be emitted by a region of the disk dominated by electron-scattering opacity. Polarization predicted by standard, smooth, thin disk models disagrees with observations. The introduction of local surface roughness brings the predicted polarization more closely into line with observations. Further, the predicted polarization of radiation escaping from a thick radiation torus agrees well with observed values.