Exploring the Central Engines of Luminous Quasars

The main power source in quasars is thought to come from matter accreting onto a supermassive black hole. This proposal concerns the signatures of the central accretion disk that are present in Xray spectra of AGN. We propose to study with XMM 4 of the most luminous known radioquiet quasars in order to ascertain the properties of the central engine in these objects. In particular, we will use reprocessing features from the disk in the form of a soft excess,iron K line, iron K edge and .Compton hump. to determine the ionisationproperties of the disk. Evidence for an increased ionisation in these most luminous of quasars will support models whereby the supermassive black hole is near to Eddingtonlimited. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]