The first systematic study of extreme accretion with XMM-Newton and NuSTAR

SuperEddington accretion periods are expected to be extremely important toexplain the fast growth of the first supermassive black holes. We propose here asystematic broadband Xray study of superEddington AGN ( Edd 15 to Edd 427) at z < 0.1 by simultaneously observing five of them with XMMNewton andNuSTAR. We use the best sample available, SEAMBHs, which contain objects withblack hole masses estimated from reverberation mapping, making the Eddingtonratio estimates extremely reliable. The broadband observations will allow toshed light on a large number of fundamental issues, such as the behaviour of thecutoff energy, of the reprocessed radiation, of the iron complex and of the softexcess at extreme Eddington ratios. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]