The 1st systematic XR Study of extreme accretion on supermassive BH with NU+XM

SuperEddington accretion periods are expected to be extremely important toexplain the fast growth of the first supermassive black holes. However,among allaccretion modes, this phase is still the least understood one,and it is stilllargely debated what are the physical properties of the accretion flow and ofthe Xray source at very high accretion rates. We propose here a systematicbroadband Xray study of superEddington AGN at z<0.1 by simultaneouslyobserving three sources with NuSTAR and XMM.These three AGN have the highestEddington ratios in the SEAMBHs sample, which contains exclusively objects withblack hole masses estimated from reverberation mapping, making the Eddingtonratio estimates extremely reliable. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]