The Nature of Soft X-Ray Weak Quasars

About 10% of the quasars are soft Xrayweak: its Xray emission is by a factor1030 fainter than in typical quasars. Different observational parameterssuggest that absorption is the primary cause of their Xray weakness, but auniform absorbing screen cannot explain the Xray and ultraviolet emission. Ourprevious XMMNewton observations of three quasars confirm that their weakness isrelated to absorption. However, our data show an absorbing column density andionization parameter, which are much higher than detected for other AGNs. Wepropose to observe the last two outstanding Xray weak quasars of the completesample of Brand, Laor and Wills et al. (2000), which will allow to rigorouslystudy the Xray absorption scenario in Xray weak quasars. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]