Molecular gas depletion timescales, t_depl = M_gas/SFR, as a function of stellar masses plotted for our low-L_IR-selected SFGs (squares) and our comparison sample of SFGs and local spirals with CO measurements from the literature (see Sect. 2.2). The molecular gas depletion timescales are computed assuming a “Galactic” CO–H₂ conversion factor for all galaxies. A t_depl–M_∗ correlation emerges for z> 1 SFGs; their best-fitting bisector linear relation, log (t_depl) = (0.52 ± 0.16)log (M_∗) + (3.25 ± 1.74), is plotted as a solid black line. The best-fitting bisector linear relation to the z = 0 COLD GASS sample from Saintonge et al. (2011) is shown with the dashed blue line.