The data in these two panels are the same as in Fig. 8. Here, the black solid lines in all three panels represent the default model where R_mol is dictated by the hydrostatic pressure (P_h) as in Fig. 9. Panel (a) shows alternative models which assume constant Q_sg = 1.3 (blue dashed line) and constant Q_sg = 1.9 (green dashed line). Panel (b) shows alternative models which assume σ_g = 14 km s⁻¹ (blue dashed line) and σ_g = 8 km s⁻¹ (green dashed line). Panel (c) shows alternative models which adopt TFR which differ by the 1σ scatter in Fig. 2. The models which adopt a TFR that is 1σ brighter and 1σ fainter are represented by the blue dashed line and the green dashed line, respectively.