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

• Published in: Monthly notices of the Royal Astronomical Society 2015-11, Vol.453 (3), p.2540-2557
• Main Authors: Johnston, Russell, Vaccari, Mattia, Jarvis, Matt, Smith, Mathew, Giovannoli, Elodie, Häußler, Boris, Prescott, Matthew
• Format: Article
• Language: English
• Subjects: Accretion disks; Algorithms; Astronomy; Constants; Information; Photometry; Probability; Slopes; Star & galaxy formation; Star formation rate; Stellar evolution; Stellar mass; Symbols; Uncertainty
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stv1715

We investigate the star formation rate (SFR) and stellar mass, M *, relation of a star-forming (SF) galaxy (SFG) sample in the XMM-LSS field to z ∼ 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 M * and have adapted it to account for the full photometric redshift probability-distribution-function uncertainty. Applying an SF selection using the D4000 index, we find evidence for strong evolution in the normalization of the SFR–M * relation out to z ∼ 3 and a roughly constant slope of (SFR $\propto M_*^{\alpha }$ ) α = 0.69 ± 0.02 to z ∼ 1.7. We find this increases close to unity towards z ∼ 2.65. Alternatively, if we apply a colour selection, we find a distinct turnover in the SFR–M * relation between 0.7 ≲ z ≲ 2.0 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 at log10(M */M⊙) ∼ 10.5, out to z ≲ 2.4 with an observed flattening beyond z ∼ 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.