ASCA AGN optical identifications

The flux limit of the subsample is 3x10^-13^erg/s/cm^2^ in the 2-10keV band. All but one of the 87 hard X-ray-selected sources are optically identified, with AGNs (including broad-line AGNs, narrow-line AGNs, and three BL Lac objects), seven clusters of galaxies, and one galactic star.

It is the largest complete sample of hard X-ray-selected AGNs at the bright flux limit. Amounts of absorption to their nuclei are estimated to be hydrogen column densities (NH) of up to 3x10^23^cm^-2^ from their X-ray spectra. Optical properties of X-ray absorbed AGNs with N_H_>1x10^22^cm^-2^ indicate the effects of dust absorption: at redshifts z<0.6, AGNs without broad H{beta} emission lines have significantly larger NH-values than AGNs with broad H{beta} emission lines.