Stacking of 24 μm sources on PACS maps in GOODS-S. Top panel: PACS/24 μm colors of sources, as measured from individual detections (black dots) and detections+stacking (colored symbols). Black solid lines and grey shaded areas represent average colors and dispersion of PACS-detected sources. Solid purple lines are polynomial fits to the stacked points. For each 24 μm flux bin the number of sources detected by PACS and the total number of MIPS 24 μm objects are quoted. Bottom panel: completeness analysis, based on the Le Borgne et al. (2009) backward-evolution model; the quoted 24 μm fluxes are in [mJy] units.