Dust temperatures and average SED. Left: the evolution of T_d in QGs. The filled blue circles mark the luminosity-weighted T_d for the stacked QGs at 0.3 < z < 2.0, including the results from G18. Filled grey triangles and squares indicate SFGs on the MS and strong starbursts from Béthermin et al. (2015). Filled and open grey circles represent the mass-averaged values and the most massive galaxies (11.0 < log(M_*/M_⊙) < 11.5, Salpeter IMF) for the star-forming sample of Schreiber et al. (2018a), respectively. The solid and dashed grey lines indicate the best fit models from Schreiber et al. (2018a) and Béthermin et al. (2015), extending the parameterisation of Magdis et al. (2012). The dotted grey line indicates the expected T_d track for a size evolution of QGs, R ∝ (1 + z)^−1.48. The track is normalised to the T_d of the z = 1.8 sample. Right: composite and template FIR SED for z > 0 QGs. The magenta circles (arrows) correspond to the photometry (3σ upper limits) of the stacked ensembles presented in Fig. 3 normalised to L_IR = 10¹⁰ L_⊙ (and M_dust = 1.11 × 10⁸ M_⊙). The DL07 and MBB model fits to the SED are shown with grey and red dashed lines. The dotted blue line correspond to the typical SED of z = 1.0 MS galaxies from Magdis et al. (2012), normalised to the same L_IR. The QG template is publicly available at www.georgiosmagdis.com/software/.