The orientation of the nuclear obscurer of the AGNs
  We examine the distribution of axis ratios of a large sample of disk galaxies
hosting type 2 AGNs selected from the Sloan Digital Sky Survey and compare it
with a well-defined control sample of non-active galaxies. We find them
significantly different, where the type 2 AGNs show both an excess of edge-on
objects and deficit of round objects. This systematical bias can not be
explained by a nuclear obscurer oriented randomly with respect to the stellar
disk. However, a nuclear obscurer coplanar with the stellar disk also does not
fit the data very well. By assuming that the nuclear obscurer having an opening
angle of ~60 degree, we find the observed axis ratio distribution can be nicely
reproduced by a mean tilt angle of ~30 degree between the nuclear obscurer and
the stellar disk.
