Spatial distribution of the ionized and excited dense molecular gas. Left: maps in the F187N filter (Pa α line) and in the F470N filter continuum subtracted (H₂ 0–0 S(9) line). Same as Fig. 6 for the vertical and horizontal lines. Vertical dotted lines in the F470N filter continuum subtracted show the DFs position as determined in Sect. 5.2.1. Units are in erg cm⁻² s⁻¹ sr⁻¹. Right: Surface brightness profiles of the Pa α (in blue) and H₂ 0–0 S(9) line (in green) as a function of the distance from the IF. The profiles of the lines are normalized to the surface brightness profiles of the F335M filter (in red). The intensities have not been corrected for dust extinction. The ALMA HCO⁺ J = 4−3 line integrated intensity profile is shown in grey. The vertical dotted-dashed lines indicate the average position of the IF and the DFs, also indicated by yellow lines in the left panels.