Emission line maps of the [NeII] – and H₂ S(2) lines (top panel) and the [Fe II] – and H₂ S(1) lines (lower panel). On both panels line emission is superimposed on an IRAC band-2 (4.5 μm) image. The positions of SMM1-a and SMM1-b (to the SE and NW, with respect to each other) from Choi (2009) are marked with crosses, and the SH spaxel size and orientation is marked as a (red) square in the lower right corner of each panel. The (magenta) filled circles show the positions of the 163 GHz H₂O maser emission (van Kempen et al. 2009), coincident with the NW lobe of the atomic emission. Contour levels are at 10–90% of the peak emission for each transition, as listed in Table 1.