Spectral energy distribution shapes for most of our sources. Literature observations are shown as filled circles, whereas our PACS observations are marked with crosses and drawn in a different hue (see Table C.1). The maxima of the SEDs lie between 10^-16 and 10^-19 W cm^-2 for all objects and thus, for better shape vizualisation, the SEDs are offset by several orders of magnitude. Objects are shown in the sequence of decreasing evolutionary parameter .