Marginal probability distribution functions of 〈D〉_BD and F′_radio. In each plot, the relative likelihood is defined such that it is unity at the dashed black line, corresponding to the most probable value of each parameter, i.e. ${⟨D⟩}_{\mathrm{B}\mathrm{D}}={0.030}_{-0.030}^{+0.034}$ and $F_{\mathrm{r}\mathrm{a}\mathrm{d}\mathrm{i}\mathrm{o}}^{{}^{\prime }}={0.088}_{-0.088}^{+0.168}$. The error bars of the parameters correspond to 68% confidence interval (CI), as represented by the blue-shaded region. The parameter value within orange shaded region can be rejected with ≥95%.