The SHEEP SURVEY: WHAT KIND OF OBJECTS MAKE UP THE X-RAY BACKGROUND

We propose to obtain XMM spectra of 35 bright sources detected in the hard (510keV) ASCA SHEEP survey over an area of 39 sq deg. These sources have not beendetected by ROSAT being the hardest sources in our sample. Snapshot (5 ksec)Chandra imaging observations as well as NOAO optical spectroscopic followupobservations have already been allocated in Chandra AO3. Hence, a relativelymodest investement of XMM time will create a unique database of hard brightsources. These are expected to be the bright (>1e13 cgs 510 keV) examples ofthe enigmatic hard Xray sources detected in deep Chandra fields which are toofaint to allow their detailed study.Therefore our sample will help us to examinein detail the astrophysics of the objects which make up the Xray background. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]