Deconvolution of the CO (18–17) maps around SMM3 and SMM4 with the instrumental point-spread function. The leftmost panel presents the initial line map. Stepwise to the right, each panel presents the residual map after subtracting the instrumental PSF at a specific location. For SMM3 (upper panels), these locations are indicated on each panel (SMM3b, SMM3c, and SMM3r). In SMM4 (lower panel), the emission is confined to a single spaxel (SMM4b). The rightmost panel corresponds to the final residual map, where flux levels are at ~10% or lower compared to the peak values in the original maps.