Investigating the Core Morphology-Seyfert Class relationship with Hubble
  Space Telescope Archival Images of local Seyfert galaxies
  The Unified Model of Active Galactic Nuclei (AGN) has provided a successful
explanation for the observed diversity of AGN in the local Universe. However,
recent analysis of multi-wavelength spectral and image data suggests that the
Unified Model is only a partial theory of AGN, and may need to be augmented to
remain consistent with all observations. Recent studies using high spatial
resolution ground- and space-based observations of local AGN show that Seyfert
class and the "core" (r<~1 kpc) host-galaxy morphology are correlated.
Currently, this relationship has only been established qualitatively, by visual
inspection of the core morphologies of low redshift (z<0.035) Seyfert host
galaxies (Malkan et al. 1998). We re-establish this empirical relationship in
Hubble Space Telescope (HST) optical imaging by visual inspection of a catalog
of 85 local (D<63 Mpc) Seyfert galaxies. We also attempt to re-establish the
core morphology-Seyfert class relationship using an automated, non-parametric
technique that combines both existing classification parameters methods (the
adapted CAS, G-M20), and a new method which implements the Source Extractor
software for feature detection in unsharp-mask images. This new method is
designed explicitly to detect dust features in the images. We use our automated
approach to classify the morphology of the AGN cores and determine that Sy2
galaxies visually appear, on average, to have more dust features than Sy1. With
the exception of this "dustiness" however, we do not measure a strong
correlation between the dust morphology and the Seyfert class of the host
galaxy using quantitative techniques. We discuss the implications of these
results in the context of the Unified Model.
