The GOGREEN Survey: Constraining the Satellite Quenching Timescale in Massive Clusters at $\mathbf{z}\gtrsim 1$

Abstract

We model satellite quenching at $z\sim 1$ by combining $14$ massive ($10^{13.8}<M_{\mathrm{halo}}/{\mathrm{M}}_{\odot }<10^{15}$) clusters at $0.8<z<1.3$ from the GOGREEN and GCLASS surveys with accretion histories of $56$ redshift-matched analogs from the IllustrisTNG simulation. Our fiducial model, which is parameterized by the satellite quenching timescale ($\ddot{I}{„}_{\mathrm{quench}}$), accounts for quenching in our simulated satellite population both at the time of infall by using the observed coeval field quenched fraction and after infall by tuning $\ddot{I}{„}_{\mathrm{quench}}$ to reproduce the observed satellite quenched fraction versus stellar mass trend. This model successfully reproduces the observed satellite quenched fraction as a function of stellar mass (by construction), projected cluster-centric radius, and redshift and is consistent with the observed field and cluster stellar mass functions at $z\sim 1$. We find that the satellite quenching timescale is mass dependent, in conflict with some previous studies at low and intermediate redshift. Over the stellar mass range probed ($M_{\star }>10^{10}{\mathrm{M}}_{\odot }$), we find that the satellite quenching timescale decreases with increasing satellite stellar mass from $\sim 1.6\mathrm{Gyr}$ at $10^{10}{\mathrm{M}}_{\odot }$ to $\sim 0.6-1\mathrm{Gyr}$ at $10^{11}{\mathrm{M}}_{\odot }$ and is roughly consistent with the total cold gas (H{\scriptsize I}+H${}_2$) depletion timescales at intermediate $z$, suggesting that starvation may be the dominant driver of environmental quenching at $z<2$. Finally, while environmental mechanisms are relatively efficient at quenching massive satellites, we find that the majority ($\sim 65-80\%$) of ultra-massive satellites ($M_{\star }>10^{11}{\mathrm{M}}_{\odot }$) are quenched prior to infall.

Key Figures: 4, 6 and 9; 16 pages; 11 figures; accepted for publication in MNRAS 26 July 2022;