X-ray weak broad-line quasars: absorption or intrinsic X-ray weakness

We propose seven short observations of Xray weak quasars, with the aim ofunderstanding the origin of their low Xray to optical ratio. The sources belongto the spectroscopically selected Hamburg Quasar Survey, and have been observedwith Chandra and in the optical. They show unusual optical properties (most ofthem have a red continuum and very high EW broad emission lines), while thenature of their Xray weakness (intrinsic or due to absorption ?) is not yetclear, because of the low signaltonoise of the Chandra spectra. Four shortobservations with XMMNewton gave the answer for four sources, showingabsorption in two cases, and an unabsorbed spectrum in the other two. This showsthat XMMNewton can unveil the nature of the Xray emission of these sources. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]