Upper panel: surface density profile derived from the stellar density maps of Gallego-Cano et al. (2020, blue diamonds). The uncertainties are measured using the corresponding uncertainty map and are only shown for a subset of data points to improve visibility. We matched the profile to the centre value of Feldmeier-Krause et al. (2017b) to convert it into units of L_⊙ pc⁻². The solid black line denotes the profile along the major axis, the dashed red line shows the profile along the minor axis, and the dot-dashed orange line shows the profile along a position angle of 45°. Middle panel: residuals of the star count data after subtracting the MGE fit. Lower panel: projected axis ratio q_proj.