SFR vs. stellar masses at three different age intervals calculated from the SFH. The color of the symbols is as in Fig. 4. The solid and dashed black lines are the M-S relation and uncertainty, respectively, derived by Elbaz et al. (2007) for SDSS galaxies at z ~ 0. The horizontal dashed red line marks the approximate threshold SFR needed to reach a log L_IR/L_⊙> 11 (excluding the AGN luminosity) based on our calibration (Sect. 5.2). Galaxies below the LIRG threshold are close companions of the sources identified as LIRGs using low angular resolution (2′) IRAS data (see Sect. 2).