MRS spectra of the star-forming region 1.1″ SE of the AGN. Top panel: ch1 to ch3 spectra extracted with a 0.3″ radius. We applied the residual fringing correction to the 1D spectra and scaling factors to stitch together the spectra of the different sub-channels. Middle and bottom panels: zoomed-in spectral regions of selected emission lines. In all panels, the rest-frame wavelengths were computed with the redshift quoted in Sect. 1 and appear redshifted with respect to the systemic velocity (see mean-velocity maps of [Ar II] and [Ne II], middle panels of Figs. 5 and 6), due to rotation.