From top to bottom and from left to right: distribution of the RVs of stars in run 1, 2, 4, 5, 7, 11, 13, 15 and 16 at t = 4.8 Myr (see Table 1). The simulated RVs include randomly generated observational uncertainties. Solid red line: pop. A (cluster 1); dotted black line: pop. B (cluster 2); dashed blue line: sum of the two components. We define RV as the velocity along the y axis (i.e. we assume that the line-of-sight coincides with the direction that maximizes the velocity shift between the two clusters). Green shaded histogram: observed RV distribution (the same as in Fig. 6 of Jeffries et al. 2014).