Plotted in black, the histogram of the 100 μm significance χ₁₀₀ for the non-excess sources of the merged DUNES_DU and DUNES_DB samples with d ≤ 20 pc (dubious sources of both samples are not included). A Gaussian with σ = 1.40, the standard deviation of the χ₁₀₀ values for these sources, is plotted in blue. In cyan, we show a Gaussian with σ = 1.02, corresponding to the subsample of non-excess sources with −2.0 <χ₁₀₀< 2.0. In red, the distribution of χ₁₀₀ for the excess sources is also displayed. This figure is an extension of Fig. 6 in E13. See text for details.