A mid-infrared statistical investigation of clumpy torus model
  predictions
  We present new calculations of the CAT3D clumpy torus models, which now
include a more physical dust sublimation model as well as AGN anisotropic
emission. These new models allow graphite grains to persist at temperatures
higher than the silicate dust sublimation temperature. This produces stronger
near-infrared emission and bluer mid-infrared (MIR) spectral slopes. We make a
statistical comparison of the CAT3D model MIR predictions with a compilation of
sub-arcsecond resolution ground-based MIR spectroscopy of 52 nearby Seyfert
galaxies (median distance of 36 Mpc) and 10 quasars. We focus on the AGN MIR
spectral index $\alpha_{MIR}$ and the strength of the 9.7 $\mu$m silicate
feature $S_{Sil}$. As with other clumpy torus models, the new CAT3D models do
not reproduce the Seyfert galaxies with deep silicate absorption
($S_{Sil}<-1$). Excluding those, we conclude that the new CAT3D models are in
better agreement with the observed $\alpha_{MIR}$ and $S_{Sil}$ of Seyfert
galaxies and quasars. We find that Seyfert 2 are reproduced with models with
low photon escape probabilities, while the quasars and the Seyfert 1-1.5
require generally models with higher photon escape probabilities. Quasars and
Seyfert 1-1.5 tend to show steeper radial cloud distributions and fewer clouds
along an equatorial line-of-sight than Seyfert 2. Introducing AGN anisotropic
emission besides the more physical dust sublimation models alleviates the
problem of requiring inverted radial cloud distributions (i.e., more clouds
towards the outer parts of the torus) to explain the MIR spectral indices of
type 2 Seyferts.
