The average normalized SEDs for the aperture classes. Results from the “PDR” class are shown in dark gray while those in the “Filament” class are shown in light gray. Where the two “PDR” and “Filament” distributions overlap, we show light gray with dark gray hatching. Lines show the average normalized SEDs for the “Entire”, Other “HII”, “PS”, and “IRDC” classes; the “IRDC” class SED is similar to that of the “Filament” class while the SEDs of the “Entire”, and “Other H II” classes are more similar to that of the “PDR” class. The “PS” class has a mean SED shape in between that of the “PDR” and “Filament” classes. The points at 8.0 μm and 24 μm are shown here although these data were not used in the fits.