Determining Inclinations of Active Galactic Nuclei Via Their Narrow-Line
  Region Kinematics - I. Observational Results
  Active Galactic Nuclei (AGN) are axisymmetric systems to first order; their
observed properties are likely strong functions of inclination with respect to
our line of sight. However, except for a few special cases, the specific
inclinations of individual AGN are unknown. We have developed a promising
technique for determining the inclinations of nearby AGN by mapping the
kinematics of their narrow-line regions (NLRs), which are often easily resolved
with Hubble Space Telescope (HST) [O III] imaging and long-slit spectra from
the Space Telescope Imaging Spectrograph (STIS). Our studies indicate that NLR
kinematics dominated by radial outflow can be fit with simple biconical outflow
models that can be used to determine the inclination of the bicone axis, and
hence the obscuring torus, with respect to our line of sight. We present NLR
analysis of 53 Seyfert galaxies and resultant inclinations from models of 17
individual AGN with clear signatures of biconical outflow. Our model results
agree with the unified model in that Seyfert 1 AGN have NLRs inclined further
toward our line of sight (LOS) than Seyfert 2 AGN. Knowing the inclinations of
these AGN NLRs, and thus their accretion disk and/or torus axes, will allow us
to determine how their observed properties vary as a function of polar angle.
We find no correlation between the inclinations of the AGN NLRs and the disks
of their host galaxies, indicating that the orientation of the gas in the torus
is independent from that of the host disk.
