A hard X-ray survey in the Lockman Hole

We propose to carry out a deep survey in hard Xrays in the Lockman Hole by complementing the 150 ksec of the PV phase observations with another 200 ksec.The scientific goals include: 1. testing the AGN origin of the Xray background by detecting hard Xrays in all soft Xray sources, 2. test specific unified scheme models for the XRB, 3. detection of virgul30 Comptonthick AGN in hard Xrays,4. detection of the hard Xray sources missing in soft Xray surveys, 5. direct determination of hard Xray source counts down to a 210 keV 2E15 erg/cm2/s and6. determination, via fluctuation analyses, of 210 keV source counts to muchfainter fluxes. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]