X-ray spectral properties of Seyfert galaxies and the unification scheme
  Aims: The unification scheme of Seyfert galaxies predicts that the observed
differences between type 1 and type 2 Seyfert galaxies are solely due to the
differing orientations of the toroidal-shaped obscuring material around AGN.
The observed X-ray spectra of Seyfert type 2s compared to type 1s are expected
to be affected by higher absorbing column density due to the edge-on view of
the obscuring torus. We study the 0.5 - 10 keV X-ray spectral properties of
Seyfert type 1s and type 2s with the aim to test the predictions of Seyfert
unification scheme in the X-ray regime. Methods: We use an optically selected
Seyfert sample in which type 1s and type 2s have matched distributions in the
orientation independent parameters of AGN and host galaxy. Results: The 0.5 -
10 keV XMM-Newton pn X-ray spectra of Seyfert galaxies are in general best
fitted with a model consists of an absorbed power-law, a narrow Gaussian fitted
to the Fe K{\alpha} emission line and an often seen soft excess component
characterized by either a thermal plasma model with temperature kT \sim 0.1 -
1.0 keV and/or a steep power-law. The 2.0 - 10 keV hard X-ray continuum
emission in several Seyfert type 2s is reflection dominated and suggests the
Compton-thick obscuration. Results on the statistical comparison of the
distributions of the observed X-ray luminosities in the soft (0.5 - 2.0 keV)
and hard (2.0 - 10.0 keV) bands, the X-ray absorbing column densities, the
equivalent widths of Fe K{\alpha} line and the flux ratios of hard X-ray to
[OIII] {\lambda}5007{\AA} for the two Seyfert subtypes are consistent with the
obscuration and orientation based unification scheme.
