Profiles of the relative brightness (normalized to 1 at a distance of 2″) for all broadband filters, along cut 3 (see Fig. 6) shown at the top. Middle panels: normalized color ratios (normalized to 1 at a distance of 2″) relative to the F770W filter, smoothed with a window size of 10 pixels, corresponding to ~0.6″, in order to limit the noise. Above ~15″ the ratios are more noisy because the brightness is near 0. Bottom panels: profiles of the optical depth difference along the third cut (see Sect. 8). On the bottom left panel is also plotted the normalized velocity-integrated intensity profiles of the CO J = 3–2 and HCO⁺ J = 4–3 lines observed with ALMA by Hernández-Vera et al. (2023).