The thick red solid line represents the luminosity limit corresponding to a criterion of a 5σ detection in at least two Herschel bands. The other solid lines are the limits for a detection at only one given wavelength (purple for 100 μm, blue for 160 μm, turquoise for 250 μm, green for 350 μm, orange for 500 μm). The dashed, dot-dash, and three-dot-dash lines indicate the infrared luminosity of a galaxie of 3 × 10¹⁰M_⊙ (our mass cut) at the center of the main sequence, a factor of 4 above it, and a factor of 10 above it, respectively.