AGN Dusty Tori as a Clumpy Two-Phase Medium: The 10 Micron Silicate
  Feature
  We investigated the emission of active galactic nuclei dusty tori in the
infrared domain, with a focus on the 10 micron silicate feature. We modeled the
dusty torus as a clumpy two-phase medium with high-density clumps and a
low-density medium filling the space between the clumps. We employed a
three-dimensional radiative transfer code to obtain spectral energy
distributions and images of tori at different wavelengths. We calculated a grid
of models for different parameters and analyzed the influence of these
parameters on the shape of the mid-infrared emission. A corresponding set of
clumps-only models and models with a smooth dust distribution is calculated for
comparison. We found that the dust distribution, the optical depth and a random
arrangement of clumps in the innermost region, all have an impact on the shape
and strength of the silicate feature. The 10 micron silicate feature can be
suppressed for some parameters, but models with smooth dust distribution are
also able to produce a wide range of the silicate feature strength.
