Ultraviolet to far infrared self-consistent analysis of the stellar populations of massive starburst galaxies at intermediate redshifts

We study in detail the properties of the stellar populations of 111 massive [log (M-*/M-circle dot) >= 10] dusty [far-infrared (FIR)-selected] starburst (SFR/SFRMS > 2) galaxies at 0.7 < z < 1.2. For that purpose, we use self-consistent methods that analyse the UV-to-FIR broad-band observations in terms of the stellar light and dust re-emission with energy-balance techniques. We find that the emission of our starburst galaxies can be interpreted as a recent star formation episode superimposed on a more evolved stellar population. On average, the burst age is similar to 80 Myr and its attenuation similar to 2.4 mag. Assuming our starburst galaxies at half their lifetimes, we infer a duration of the starburst phase of similar to 160 Myr. The median stellar mass and star formation rate (SFR) are log (M-*/M-circle dot) similar to 10.6 and similar to 220 M(circle dot)yr(-1). Assuming this SFR and the inferred duration of the starburst phase, the stellar mass added during this phase corresponds to similar to 40 per cent the median stellar mass of our sample. The young-population age determines the position of our galaxies in the M-*-SFR plane. Galaxies located at the largest distances of the MS present shorter young-population ages. The properties of the underlying stellar population cannot be constrained accurately with our broad-band data. We also discuss the impact of including the FIR data and energy-balance techniques in the analysis of the properties of the stellar populations in starburst galaxies.

Automated summary

In this study, we investigate the properties of the stellar populations of 111 massive dusty starburst galaxies at 0.7 < z < 1.2. We find that these galaxies exhibit a recent star formation episode superimposed on a more evolved stellar population. The duration of the starburst phase is estimated to be around 160 million years, with the added stellar mass accounting for approximately 40% of the median stellar mass in the sample.