Concentration profiles of cluster’s stellar (n_⋆) and gaseous (n_𝑔as) material are shown for different SFEs, ranging from 0.15 to 0.35 and 0.99. The dotted and dash-dotted black vertical lines represent the radii enclosing 50% and 90% of the cluster’s stellar mass, respectively. The dashed black vertical line marks the simulated cluster boundary, r_cluster, which is defined as 20 ⋅ a_p. For the r_apo = 10 kpc and λ₀ = 0.09 models (see Sect. 2.4), this corresponds to ~19.5 pc.