The Host Galaxies of Narrow-Line Seyfert 1s: Nuclear Dust Morphology and   Starburst Rings
  We present a study of the nuclear morphology of a sample of narrow- and broad-line Seyfert 1 galaxies (NLS1's and BLS1's) based on broad-band images in the Hubble Space Telescope archives. In our previous study, we found that large-scale stellar bars at > 1 kpc from the nucleus are more common in NLS1's than BLS1's. In this paper we find that NLS1's preferentially have grand-design dust spirals within approx. 1 kpc of their centers. We also find that NLS1's have a higher fraction of nuclear star-forming rings than BLS1's. We find that many of the morphological differences are due to the presence or absence of a large-scale stellar bar within the spiral host galaxy. In general, barred Seyfert 1s tend to have grand-design dust spirals at their centers, confirming the results of other researchers. The high fraction of grand-design nuclear dust spirals and stellar nuclear rings observed in NLS1's host galaxies suggests a means for efficient fueling of their nuclei to support their high Eddington ratios. 
R. P. Deo, D. M. Crenshaw & S. B. Kraemer