Basic structural planes for Mod-A described by Eqs. (25)–(30). In this case we include the effect of the relative kinetic energy of the incoming object. The parameters η, ϵ, and λ are randomly varied in the intervals 0.1 ≤ η ≤ 0.3, 0.01 ≤ ϵ ≤ 0.03, and 0.1 ≤ λ ≤ 0.3, and summed up N times. In addition to this, the expression for the luminosity contains the parameter θ which is randomly varied at each step in the interval 1 ≤ θ ≤ 3. This parameter is meant to simulate the effect of age of the luminosity of the incoming object. No integration on the number of steps N is performed. The meaning of the symbols and colour-coding are as in Fig. 11. Left panel: I_e vs R_e plane. Middle panel: L_V vs σ plane. The dashed line is the best fit limited to the models in four small clouds. Right panel: R_e vs M_s plane. The filled circles are the original seed data.