Solutions of Eqs. (1)–(12) for different CO masses (see legend) with L_obs in the range 2−100 × 10³⁹ erg s⁻¹. From top to bottom: (i) the mass-transfer rate (ṁ) of a ULX as a function of the isotropic-equivalent luminosity when observed face-on (L_obs). (ii) The beaming factor (b) as a function of L_obs; the flattening occurs at ṁ = 8.5. (iii) The radius of the region producing the soft component as a function of ṁ for different models (line styles; see lower legend). (iv) The effective temperature of the blackbody region as a function of the ṁ; the dotted-dashed line shows the inner temperature of the disk.