Distribution of γ_{Low − zZ} (left panel) and q_{PAH_Low − zZ} (right panel) dust parameters from Draine & Li’s models for the Low-zZ galaxy sample. The γ_{Low − zZ} distribution peaks at 0.75 ± 0.07 and most of the q_PAH = 0.47, which is the lowest value in Draine & Li’s models. γ_{Low − zZ} is assumed to be valid for the Hi-z LBG sample, and q_{PAH_Low − zZ} is fully consistent with our assumed q_{PAH_Hi−z}.