Panels show posterior distributions in tw for each ‘gold’ member galaxy of XLSSC 122, having marginalized over Mstar. For convenience, the same colour scheme is employed as in Extended Data Fig. 2. In each panel the solid, dashed and dotted curves display, respectively, SED models characterized by AV = 0.0, 0.3 and 0.5. The vertical dashed line in each panel indicates the age of the Universe at z = 1.98.