Simulations of the serendipitous X-ray sky as seen by XMM with the EPIC-pn camera with 350ks exposure (left:0.5-2 keV right:2-10 keV)
Below, on the left, the spectrum of a broadline QSO at z=1.54(obtained at the INT with the IDS) and on the right, the spectra of a narrowline QSO at z=1.246(obtained at the WHT with the ISIS). The emission lines seen are CIV 1550Å, HeII 1640Å and CIII] 1909Å. These spectra emphasize the difference between soft and hard wavelengths.