Models of the dust SEDs of sources PJ231−20 (left panels) and PJ308−21 (right panels). Upper panels: circles and diamonds indicate continuum data obtained in this work and those obtained from the ALMA Cycle 6 [CII]_158 μm observations (Decarli et al. 2017), respectively. Downward arrows indicate 3σ upper limits. The best-fit modified blackbody model is indicated with a solid red line for the quasars, and the blue and cyan lines show the models for companion galaxies assuming T_dust = 47 K and 35 K, respectively. The shadowed areas show the 1σ confidence intervals. Green bands indicate the ALMA frequency bands redshifted to the quasar-companion pair rest frame (z_pair = [z_QSO + z_comp]/2). Lower panels: posterior probability distributions of the free parameters (red for quasars, blue and cyan for companions). The vertical lines indicate the best-fit values computed as 50th percentiles of the distributions. The best-fit values with their uncertainties are also reported.