Dust correction factors over 0 < z < 3 in massive star-forming galaxies derived from a stacking analysis of Herschel data

Abstract

We use a stacking analysis in Herschel/PACS to study the accuracy of several dust-correction factors that are typically employed to estimate the total star-formation rate (SFR) of high-redshift, massive, star-forming (SF) galaxies. We also analyze what stacking suggests about the relation between SFR and stellar mass and the redshift evolution of the specific SFR (sSFR = SFR/M_∗). We find that the dust properties of massive SF galaxies evolve with redshift, that is, galaxies at z ~ 2-3 are more attenuated than at z ~ 1 for a given UV continuum slope and stellar mass. As a consequence, a single IRX-β or dust-mass relation cannot be used to recover the total SFR of massive SF galaxies at 0 ≲ z ≲ 3. This might have implications for studies at higher redshifts, where a single IRX-β relation derived for local starbursts is usually assumed to be valid. However, we find evidence that the local relations might be valid at least up to z ~ 1, where bluer and less massive galaxies can be detected through stacking. The spectral energy distribution fitting procedure with stellar population templates gives overestimated values (about 0.3-0.5 dex in log SFR) of the dust-corrected SFR at all redshifts studied here. We find that the slope of the main-sequence of star formation is flatter than previously found in massive galaxies with log (M_∗/M_⊙) ≥ 10, and the redshift evolution of the sSFR reported in previous works in massive galaxies is well recovered.

Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendix A is available in electronic form at http://www.aanda.org