Surface densities of red IRAC sources estimated in annuli of width 10″ centered on the BRCGs. The stack for the entire SPHerIC sample (82 candidates) is indicated by the red line, while the blue line is for the densest candidates (with Σ_60″ > Σ_SpUDS + 3σ). In green we show the profile around red SPIRE sources in the COSMOS field. The solid black line indicates the mean surface density Σ_SpUDS of IRAC red sources in the SpUDS survey, derived from a Gaussian fit as described in the text, while the dashed black lines indicate Σ_SpUDS ± σ_SpUDS. Error bars indicate the scatter and not the error on the mean value. The blue and green lines are offset in angular separation for clarity.