X-ray spectra of high redshift quasars

GT It is proposed to measure the Xray spectrum of a number of quasars withredshift virgul3 in order to probe quasar emission to rest energies as high as 50keV, search for evolution in quasar spectral emission commensurate with theknown evolution in luminosity, and search for environmental and otherdifferences between radio quiet and radio loud quasars. The observation ofSP891107+487 is split into two self contained segments of 45ks and 35ks inorder to fit within the maximum contiguous observing slot. They should beobserved as close together in time as possible (contiguous desirable) to samplethe same intensity state of the source. Some observations use Grism andnondefault OM windows. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]