We present Chandra and XMM-Newton observations of 12 bright ( f ( 2 - 10 keV ) > 10 ^ { -13 } erg cm ^ { -2 } s ^ { -1 } ) sources from the ASCA SHEEP ( Search for the High Energy Extragalactic Population ) survey .
Most of these have been either not observed or not detected previously with the ROSAT mission and therefore they constitute a sample biased towards hard sources .
The Chandra observations are important in locating with accuracy the optical counterpart of the X-ray sources .
Optical spectroscopic observations show that our sample is associated with both narrow-line ( NL ) ( six objects ) , and Broad-Line ( BL ) AGN ( five objects ) with one source remaining unidentified .
Our sources cover the redshift range 0.04 to 1.29 spanning luminosities from 10 ^ { 42 } to 10 ^ { 45 } erg s ^ { -1 } ( 2-10 keV ) .
The NL sources have preferentially lower redshift ( and luminosity ) compared with the BL ones .
This can be most easily explained in a model where the NL AGN are intrinsically less luminous than the BL ones in line with the results of Steffen et al .
The X-ray spectral fittings show a roughly equal number of obscured ( N _ { H } > 10 ^ { 22 } cm ^ { -2 } ) and unobscured ( N _ { H } < 10 ^ { 22 } cm ^ { -2 } ) sources .
There is a clear tendency for obscured sources to be associated with NL AGN and unobscured sources with BL ones .
However , there is a marked exception with the highest obscuring column observed at a BL AGN at a redshift of z=0.5 .