  We study the hard X-ray emission of two samples of Seyfert 2 galaxies with
and without Polarized Broad Lines (PBL). In the hard X-ray domain, absorption
effects do not significantly modify the intrinsic emission allowing us a direct
access to the central engine. The purpose of this study is to compare the
primary emission of the two Seyfert 2 subclasses in order to investigate the
nature of their central engine and to test unified models according to which
they both have a hidden Seyfert 1 nucleus. We compute the average hard X-ray
spectra of Seyfert 2 galaxies with and without PBL observed with
  BeppoSAX/PDS (15-136 keV).
  The two spectra have a common general behavior at first sight, but
investigating deeper we find differences in the intrinsic properties of the two
categories of Seyfert 2 galaxies. Sy 2 with polarized broad lines have physical
conditions close to those of Sy 1 galaxies whereas Sy 2 without PBL differ
substantially, suggesting that they may have a particular place in the scheme
of Seyfert galaxies.
