Building on three previous successful PhD projects, this work will very substantially increase the sample size of AGN
(to over 700). Thereby it will be possible, for the first time, to investigate the importance of key physical parameters
such as Eddington ratio and black hole spin, on the observed multi-frequency spectral energy distributions. In addition, and
complementary to this, the student will use variability properties to constrain the emission mechanisms involved. The outcomes of these studies will be interpreted in the context of state-of-the-art accretion disc models developed here in
Durham. It is anticipated that proposals to obtain new observations of selected AGN from the sample will be made to both
satellite facilities eg. the Hubble and XMM-Newton, and to large ground based telescopes such as the VLT and the Gemini 8m's,
to which we have access by virtue of existing collaborations.