Vertical broad-line region structure in nearby active galactic nuclei
  Broad emission lines are emitted in the surroundings of supermassive black
holes in the centers of active galactic nuclei (AGN). This region is spatially
not resolved. We intend to get information on the structure and geometry of
this broad emitting line region (BLR) based on line profile observations. We
model the rotational and turbulent velocities in the line-emitting regions
based on observed full-width at half maximum line values (FWHM) and
{\sigma}_{line} of the variable broad emission lines in four nearby AGN: NGC
3783, NGC 7469, NGC 5548, and 3C 390.3. On the basis of these velocities, we
estimate the height of the line-emitting regions above the midplane in context
with their distances from the center. The H{\beta} lines are emitted in a more
flattened configuration above the midplane in comparison to the highly ionized
lines. The H{\beta} lines originate at heights of 0.7 to 1.6 light-days and at
distances of 1.4 to 24 light-days with height/distance (H/R) ratios of only
0.07 to 0.5. The highly ionized lines originate at smaller radii than the
H{\beta} lines and/or at greater distances above the midplane with H/R values
of 0.2 to 1.7. In total, the emission lines do not originate in a thin
atmosphere of an accretion disk but rather at very extended regions above an
accretion disk. The observed geometries of the line-emitting regions resemble
the geometries of accretion disk wind models. Furthermore, the angle of the
central opening cone (generated by the emitting regions of the highly ionized
lines) is small for those galaxies with slow rotational velocities and
increases with the rotation velocity of the central region. The derived
geometries of the line-emitting regions of all four AGN are consistent with the
geometries that are predicted in outflowing disk wind models.
