Left panel: U_min parameter of Draine & Li (2007) obtained with CIGALE (Noll et al. 2009) using the full photometric coverage (ordinate) or removing PACS data (abscissa). The dashed line shows a linear relation between the two quantities and the black cross in the bottom right corner shows the average errors in the fit. Middle panel: median SED with 16th and 84th percentiles (dotted line) obtained using the full photometric coverage (black solid) or removing PACS data (red dashed line). Right panel: cold dust in thermal equilibrium within the ISM () parameter obtained with MAGPHYS (da Cunha et al. 2008) using the full photometric coverage (ordinate) or removing PACS data (abscissa). The dashed line shows a linear relation between the two quantities and the black cross in the bottom right corner shows the average errors in the fit.