X-ray spectroscopy at the quasar era

We propose to exploit the superior sensitivity and spectral resolution of the instruments onboard XMM to perform a detailed study of a sizeablesample of radioquiet quasars at redshifts (z 12) where the effects of cosmological evolution become extremely important. More specifically we want to explore the photon index lron line intensity luminosity parameter space in a region unexplored by the previous missions.The proposed observations will allow to put strong constraints on the evolutionof the Xray spectral slopes and iron line intensity and ionization state. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]