Normalized flux excess in the 8.6 μm and 11.3 μm PAH bands (top and bottom panels, respectively). The width of the lines represents the ±1σ residuals of the PAH and continuum windows (see Sect. 4.1). The x-axis is parallel to the slit (i.e., its spatial dimension), and the zero point is the object's center (the star). Note that negative values indicate that the flux in the continuum windows is greater than that in the PAH window. This is caused by silicate emission in the continuum window.