0120214

By many of their properties radio quiet quasars (RQQs) occupy apoorly understood intermediary position between Seyfert 1 galaxies (Sy1s) and radio loud quasars (RLQs). In the X-ray domain there are however several notable differences between these 3 categories of Active Galactic Nuclei (AGN).We propose to observe with INTEGRAL the three brightest RQQs in the X-ray band E 1821+643 HE 1029-1401 and MR 2251-178} in order to measure the spectral shape of their hard X-ray emission which is not well known up to now. Our aim is: a) to test thepresence of Compton reflection components ionized or neutral and b)to measure the shape and energy of the high energy spectral cut-off.The scientific goal of this proposal is to obtain a better understanding of the hard spectral energy distribution of RQQs in particular at high energies. We will thereby gain deeper insight on the relationship between RQQs Sy1s and RLQs.This will be achieved by taking a single exposure of 500 ksper quasar. [truncated! Please see actual data for full text]