The GOGREEN survey: the environmental dependence of the star-forming galaxy main sequence at 1.0 &lt; <i>z</i> &lt; 1.5
Lyndsay Old, Michael L. Balogh, R. F. J. van der Burg, A. Biviano, H. K. C. Yee, Irene Pintos-Castro, Kristi Webb, Adam Muzzin, Gregory Rudnick, Benedetta Vulcani, Bianca M. Poggianti, Michael C. Cooper, Dennis Zaritsky, Pierluigi Cerulo, Gillian Wilson, J. Chan, C. Lidman, Sean McGee, R. Demarco, Ben Forrest, Gabriella De Lucia, David Gilbank, Egidijus Kukstas, Ian G. McCarthy, P. Jablonka, Julie Nantais, Allison Noble, Andrew M M Reeves, Heath Shipley
Abstract
ABSTRACT We present results on the environmental dependence of the star-forming galaxy main sequence in 11 galaxy cluster fields at 1.0 &lt; z &lt; 1.5 from the Gemini Observations of Galaxies in Rich Early Environments Survey (GOGREEN) survey. We use a homogeneously selected sample of field and cluster galaxies whose membership is derived from dynamical analysis. Using [$\rm{O{\small II}}$]-derived star formation rates (SFRs), we find that cluster galaxies have suppressed SFRs at fixed stellar mass in comparison to their field counterparts by a factor of 1.4 ± 0.1 (∼3.3σ) across the stellar mass range: 9.0 &lt; log (M*/M⊙) &lt; 11.2. We also find that this modest suppression in the cluster galaxy star-forming main sequence is mass and redshift dependent: the difference between cluster and field increases towards lower stellar masses and lower redshift. When comparing the distribution of cluster and field galaxy SFRs to the star-forming main sequence, we find an overall shift towards lower SFRs in the cluster population, and note the absence of a tail of high SFR galaxies as seen in the field. Given this observed suppression in the cluster galaxy star-forming main sequence, we explore the implications for several scenarios such as formation time differences between cluster and field galaxies, and environmentally induced star formation quenching and associated time-scales.