Effect of the star formation histories on the SFR-M_* relation at z ≥ 2

We investigate the effect of different star formation histories (SFHs) on the relation between stellar mass (M_∗) and star formation rate (SFR) using a sample of galaxies with reliable spectroscopic redshift z_(spec)> 2 drawn from the VIMOS Ultra-Deep Survey (VUDS). We produce an extensive database of dusty model galaxies, calculated starting from a new library of single stellar population (SSPs) models, weighted by a set of 28 different star formation histories based on the Schmidt function, and characterized by different ratios of the gas infall timescale τ_(infall) to the star formation efficiency ν. Dust extinction and re-emission were treated by means of the radiative transfer calculation. The spectral energy distribution (SED) fitting technique was performed by using GOSSIP+, a tool able to combine both photometric and spectroscopic information to extract the best value of the physical quantities of interest, and to consider the intergalactic medium (IGM) attenuation as a free parameter. We find that the main contribution to the scatter observed in the SFR-M_∗ plane is the possibility of choosing between different families of SFHs in the SED fitting procedure, while the redshift range plays a minor role. The majority of the galaxies, at all cosmic times, are best fit by models with SFHs characterized by a high τ_(infall)/ν ratio. We discuss the reliability of a low percentage of dusty and highly star-forming galaxies in the context of their detection in the far infrared (FIR)