The basic question I want to address is : “What mechanism or mechanisms accelerate the gas in the narrow line region of active galaxies, yielding the observed profile shapes.” At the present time there is no generally accepted answer to this question. Part of the problem dates back to the first few Seyferts that were discovered which, in retrospect, seem to have had anomalously broad lines. For example NGC 1068, MKN 3, and MKN 78 have [OIII] λ 5007 FWHM ~ 1000 km s-1, which is clearly greater than anything associated with a normal galaxy velocity fields. An obvious implication was that these high velocities were in some way related to the activity. This view was reinforced by the discovery of a correlation between [OIII] FWHM and non-thermal radio luminosity (Wilson and Willis 1981). When many radio sources were found to have linear double or triple morphology (e.g. Ulvestad and Wilson 1984a,b), a natural explanation seemed to be outflowing radio jets which stir up the narrow line region and thus generate the correlation between line width and radio luminosity.
Resolved Spectroscopy of the Narrow-Line Region in NGC 1068: Kinematics of the Ionized Gas