X-Ray properties of the most luminous obscured QSOs

Using the largest Spitzer surveys (SWIRE & NDWFS) we uncovered an exceptionalpopulation of zvirgul2 obscured and extremely luminous QSOs. We propose XMMNewtonobservations of 11 sources from our unique sample of the 15 most luminousobscured QSOs currently known. These data will enable us to place constraints onthe space density of obscured and extremely luminous QSOs, their contribution tothe Xray background, the highz and highL absorption distribution, and theobscured AGN fraction. The properties of the absorber will be also investigatedby analyzing the dependency of the dust covering factor with the AGN luminosity,and comparing dust extinction with Xray absorption. In addition, theseobservations will provide new templates for obscured QSOs. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]