Gas density distribution for the 18 reference models (see Table 2) after 100 Myr of evolution. The nine panels on the left represent the models with high initial gas fraction (models “H”); the nine on the right are the corresponding models with low initial fraction of gas (models “L”). For each sequence of nine panels, the first column represents models with 10⁷   M_⊙ of initial baryonic mass, the middle column shows the gas distribution for models with mass 10⁸M_⊙, and the right-hand column displays the models with 10⁹M_⊙. The top rows of models are characterized by a roundish initial distribution (models “R”, with b/a = 5). The middle rows show models with b/a = 1 (models “M”), and the bottom rows are characterized by b/a = 0.2 (flat models or “F”). In the top-right corner of each panel, the model designation is also indicated. For each set of nine models, the left-hand strip shows the (logarithmic) density scale (in g cm^-3).