  Using a sample of 24264 optically selected AGNs from the SDSS DR7 database,
we characterise how the profile of the [OIII] emission line relates to
bolometric luminosity (L_Bol), Eddington ratio, radio loudness, radio
luminosity (L_Rad) and optical class (Sy 1/2) to determine what drives the
kinematics of this kpc-scale line emitting gas. Spectral stacking is used to
characterise how the average [OIII] profile changes as a function of these
variables. After accounting for the correlation between L_Bol and L_Rad, we
report that L_Rad has the strongest influence on the [OIII] profile, with
moderate radio luminosity AGNs (log(L_Rad)=23-25 W/Hz) having the broadest
[OIII] profiles. When binned according to Eddington ratio, only AGNs in our
highest bin (i.e., R_Edd>0.3) show any signs of having broadened [OIII]
profiles, although the small numbers of such extreme AGNs mean we cannot rule
out that other processes (e.g., radio jets) are responsible for this
broadening. We find no significant difference between the [OIII] profiles of
broad and narrow-line Seyfert 1s. The [OIII] profiles of Sy 1 and 2 AGNs show
the same trends in terms of line width, but Sy 1 AGNs display a much stronger
blue wing, which we interpret as evidence of outflowing ionised gas. Using
multi-component line fitting we calculate the proportions of AGNs with broad
[OIII] profiles, finding that moderate radio luminosity AGNs are roughly 5
times more likely to have extremely broad [OIII] lines (FWHM>1000km/s) compared
to lower L_Rad AGNs. Our results are consistent with the most disturbed gas
kinematics being induced by compact radio cores (rather than powerful radio
jets), although broadened [OIII] lines are also present, but much rarer, in low
L_Rad systems (<10^23 W/Hz). Our catalogue of multi-component fits is freely
available as an online resource.
