Suzaku View of the Swift/BAT Active Galactic Nuclei (I): Spectral
  Analysis of Six AGNs and Evidence for Two Types of Obscured Population
  We present a systematic spectral analysis with Suzaku of six AGNs detected in
the Swift/BAT hard X-ray (15--200 keV) survey, Swift J0138.6-4001,
J0255.2-0011, J0350.1-5019, J0505.7-2348, J0601.9-8636, and J1628.1-5145. This
is considered to be a representative sample of new AGNs without X-ray spectral
information before the BAT survey. We find that the 0.5--200 keV spectra of
these sources can be uniformly fit with a base model consisting of heavily
absorbed (log $N_{\rm{H}} > 23.5 \rm{cm}^{-2}$) transmitted components,
scattered lights, a reflection component, and an iron-K emission line. There
are two distinct groups, three "new type" AGNs (including the two sources
reported by \citealt{Ueda2007}) with an extremely small scattered fraction
($f_{\rm{scat}} < 0.5%$) and strong reflection component ($R = \Omega / 2 \pi
\gtrsim 0.8$ where $\Omega$ is the solid angle of the reflector), and three
"classical type" ones with $f_{\rm{scat}} > 0.5%$ and $R \lesssim 0.8$. The
spectral parameters suggest that the new type has an optically thick torus for
Thomson scattering ($N_{\rm{H}} \sim 10^{25} \rm{cm}^{-2}$) with a small
opening angle $\theta \sim 20^{\circ}$ viewed in a rather face-on geometry,
while the classical type has a thin torus ($N_{\rm{H}} \sim 10^{23-24} \
\rm{cm}^{-2}$) with $\theta \gtrsim 30^{\circ}$. We infer that a significant
number of new type AGNs with an edge-on view is missing in the current all-sky
hard X-ray surveys.
