Left panel: Ne⁺ abundance (relative to hydrogen nuclei). The black contour encloses the region in the disk where the electron density exceeds the critical density for the collisional excitation of the 12.8 μm line. Central panel: optical depth of the line (blue) and of the continuum (black) in the top mini-panel, below is the cumulative flux of the line, which shows which percentage of the final flux is built and where, the lower mini-panel shows again the ionized neon density, the contour indicates where the contribution to the line flux goes vertically from 15% to 85% at every radius. Right panel: line profile and image for a distance of 140 pc and an inclination of 45°.