Star-formation rate as a function of stellar mass for spectroscopically confirmed absorbing galaxies, colour-coded by redshift. Squares indicate the results of this work; circles refer to work by others. Triangles represent CO detected galaxies. For reference, we plot the Whitaker et al. (2014) redshift-dependent star-forming main sequence for two representative redshift ranges together with their 1σ- and 3σ scatter, represented by the dark- and light- shaded regions centred on each relation, respectively. See text in Sect. 4.4 for more details. The object encircled in red represents the outlier from Q 1209+107 PA2.