Differential size distribution of the identified features’ energy rate in logarithmic scale representing N = 4136 identified features (diamonds). A powerlaw index α = 1.50 ± 0.02 is found, having goodness-of-fit χ² = 14.28; the error is calculated as , where the number of features of the fitted function is NF = 3818 (dashed line), excluding data with energy rate less than background value x₀ = 4 × 10¹⁷ erg / s.