If both components of the binary system are within a few arcseconds if each other,  we have to fit a sum of two Gaussians. All fits are visually inspected. Due to the distortion corrections done in the data pipeline, the position of the peak of the Gaussian changes slightly with wavelength in a smooth manner. The scatter in the fit results can be taken as an estimate of uncertainty of our fits. We search for changes of the fitted position of the Gaussian, i.e. changes in the mean position of the emission around the wavelength of forbidden emission lines (FELs) (see table 1). Limiting our search in this way reduces the rate of false-positives. Since FELs can only be formed in low-density environments, they are tracers of outflows and cannot originate on the star. 
Below, we show those data as position-velocity-diagrams (PVD), where the origin of the especial coordinate is set on the position of the brightest star and the velocity is derived from the rest-wavelength of the a feature and the radial velocity of the star. In a PVD, resolved FEL emission is seen as  a bulge in the vicinity of the rest wavelength in the emission line, if the direction of the slit roughly aligns with the direction of the jet.