the frequently observed asymmetric blue wing of [\[\]]{} (Greene & Ho 2005)[^2]. The profile of [\[\]]{} is also expected to be a poor representation of the profile of [\[\]]{} (and hence narrow [H$\alpha$]{} and [H$\beta$]{}) if the narrow-line region is stratified in density (see discussion in Greene & Ho 2005). Therefore, as with [H$\alpha$]{}, we use the template built from [\[\]]{} to model narrow [H$\beta$]{}. The [H$\beta$]{} centroid is fixed relative to the narrow [H$\alpha$]{} position while its flux is limited by the value appropriate for Case B$\arcmin$ recombination ([H$\alpha$]{} = 3.1 [H$\beta$]{}; Osterbrock 1989). We simultaneously fit [\[\]]{} using a two-component Gaussian (identical for both lines of the doublet), one for the core and another for the blue wing, as described in Greene & Ho (2005). Finally, the broad [H$\beta$]{} profile is modeled as a multi-component Gaussian, analogous to [H$\alpha$]{}. While in general we find that this procedure provides an acceptable fit to the entire region, there were some cases ($\sim 20$) for which we could not obtain an acceptable fit for the narrow [H$\beta$]{} using the [\[\]]{} model; this may be due to gross variations in spectral resolution between the blue and red ends of the spectrum. In 