SHEEP : the ASCA 5 - 10 keV survey

We present the first results of the hard (5-10 keV) ASCA GIS survey SHEEP (Search for the High Energy Extragalactic Population). We have analysed 149 fields covering an area of 39 deg 2 detecting 69 sources. Several of these appear to be associated with QSOs and Seyfert-1 galaxies but with hard X-ray spectra, probably due to high absorption (N H > 10 22 cm −2) Indeed, the hardness ratio analysis shows that the spectra of the majority of our sources can be represented with a " scatterer " model similar to obscured Seyfert galaxies locally. According to this model, our sources present high intrinsic absorption (N H ∼ 10 23) but also significant amounts of soft X-ray emission coming from scattered light.