English

The evolving relation between star-formation rate and stellar mass in the VIDEO Survey since $z=3$

Astrophysics of Galaxies 2015-09-16 v1 Cosmology and Nongalactic Astrophysics

Abstract

We investigate the star-formation rate (SFR) and stellar mass (MM_*) relation of a star-forming (SF) galaxy sample in the XMM-LSS field to z3.0z\sim 3.0 using the near-infrared data from the VISTA Deep Extragalactic Observations (VIDEO) survey. Combining VIDEO with broad-band photometry, we use the SED fitting algorithm CIGALE to derive SFRs and MM_* and have adapted it to account for the full photometric redshift PDF uncertainty. Applying a SF selection using the D4000 index, we find evidence for strong evolution in the normalisation of the SFR-MM_* relation out to z3z\sim 3 and a roughly constant slope of (SFR Mα\propto M_*^{\alpha}) α=0.69±0.02\alpha=0.69\pm0.02 to z1.7z\sim 1.7. We find this increases close to unity toward z2.65z\sim2.65. Alternatively, if we apply a colour selection, we find a distinct turnover in the SFR-MM_* relation between 0.7z2.00.7\lesssim z\lesssim2.0 at the high mass end, and suggest that this is due to an increased contamination from passive galaxies. We find evolution of the specific SFR (1+z)2.60\propto(1+z)^{2.60} at log(M)\log(M_*)\sim10.5, out to z2.4z\lesssim2.4 with an observed flattening beyond zz\sim 2 with increased stellar mass. Comparing to a range of simulations we find the analytical scaling relation approaches, that invoke an equilibrium model, a good fit to our data, suggesting that a continual smooth accretion regulated by continual outflows may be a key driver in the overall growth of SFGs.

Keywords

Cite

@article{arxiv.1507.07503,
  title  = {The evolving relation between star-formation rate and stellar mass in the VIDEO Survey since $z=3$},
  author = {Russell Johnston and Mattia Vaccari and Matt Jarvis and Mathew Smith and Elodie Giovannoli and Boris Häußler and Matthew Prescott},
  journal= {arXiv preprint arXiv:1507.07503},
  year   = {2015}
}

Comments

19 pages, 18 figures, accepted for publication in MNRAS