Stacked 870 μm maps (in units of mJy   beam^-1) on the 24 μm positions for the cluster fields with MIPS observations, overlaid with signal-to-noise contours. The white contours range between 3σ and 13σ with an increment of 2σ, while the black countours show the  − 3σ level. The maps have not been corrected for gravitational magnification. The fifth map is the coadded signal of the four individual stacked maps, which yields a 14.5σ-detection. In Table 6 we present fits to the stacked maps.