Infrared (8−1000μm) luminosity (top) and T_dust (bottom) as a function of redshift. In both panels, the horizontal blue dashed line shows the sample median (log (L_IR/L_⊙) = 12.61 and T_dust = 39.7 K). The red filled circles represent the mean values of the binned data (each bin contains 18 SMGs, except the highest redshift bin, which contains 16 SMGs), with the error bars showing the standard errors of the mean values (mostly smaller than the size of the data points in the top panel). The red dashed curve in the top panel indicates the best-fit function to the binned data, log (L_IR/L_⊙) ∝ (1 + z)^{0.09 ± 0.01}. The solid lines show the lower IR luminosity limits calculated for the 4σ flux density limit of 5 mJy at the initial AzTEC selection wavelength of 1.1 mm. These L_IR limits were computed assuming the local ULIRG template SEDs of Casey (2012), and are plotted at four different dust temperatures of 20 K (yellow), 30 K (magenta), 40 K (cyan), and 50 K (green).