Cross-dispersion profiles along the SL slit of the Spitzer/IRS observation 16205568. The histogram shows the emission as a function of the spatial position along the slit, in pixel units (1 px = 1.8′′). The spatial profile is modeled by two slightly extended sources, one of which corresponds to NW (blue, left) and the other to SE (red, right). The profile is shown for the entire integrated spectral order of module SL1 (~8−14 μm; top) and for the [S iv] 10.5 μm line only (bottom). Left corresponds to north in Fig. 4.