ASCA OBSERVATIONS OF TYPE-2 SEYFERT-GALAXIES - III - ORIENTATION AND X-RAY-ABSORPTION

We discuss the spectral properties of a sample of type 2 Seyfert galax ies based upon the analysis of ASCA data. In this paper, we consider t he sources for which the X-ray spectra appear to be dominated by the n uclear continuum, transmitted through a large column of absorbing mate rial. We find that both Seyfert 2 galaxies and narrow emission line ga laxies (NELGs) show iron Ka line profiles indicative of reprocessing o f nuclear X-rays in a face-on accretion disk. Such line profiles are a lso observed in Seyfert 1 galaxies. This result is contrary to unifica tion models, which would predict the inner regions of transmitted Seyf ert 2 galaxies to be observed edge-on. This raises some questions as t o the orientation of the circumnuclear absorber. If the observed diffe rences between Seyfert 1 and 2 galaxies and NELGs are not due to diffe rences in the orientation of the absorbing material, then we suggest t hat differences in dust composition and grain size, and in the density of the circumnuclear gas, could be of primary importance.