Comparison of the masses of the two-component merging groups. In the top panel the more massive component is shown on the x-axis and the less massive one on the y-axis. The sample is divided into three subsamples based on the distance between components, normalized with the R₂₀₀: D = d/ max(R_200,1,R_200,2), where d is the distance between two components. The one-to-one relationship is denoted with a grey line. The bottom panel shows the ratio of the masses as a function of the more massive component.