ZFIRE - The gas inflow inequality for satellite galaxies in cluster and field haloes at z=2

Gas inflow into galaxies should affect the star formation and hence the evolution of galaxies across cosmic time. In this work, we use TNG100 of the IllustrisTNG simulations to understand the role of environment on gas inflow rates in massive galaxies at z >= 2. We divide our galaxies (log (M-*/M-circle dot) = 10.5) into cluster (log M-halo/M-circle dot >= 13) and field (log M-halo/M-circle dot < 13) galaxies at z = 2 and further divide into centrals and satellites. We track their gas inflow rates from z = 6 to 2, and find that the total gas inflow rates of satellite galaxies rapidly decline after their infall into cluster haloes as they reach the cluster centre. At z = 2, the gas inflow rate of cluster satellite galaxies is correlated with the cluster-centric radii and not the host halo mass. In contrast, the gas inflow rate in centre is strongly correlated with the host halo mass at z >= 2. Our study indicates that between redshifts 6 to 2, the gas that is normally accreted by the satellite galaxies, is redirected to the centre of the cluster halo as inflows to the cluster centrals and forming the intracluster medium. Our analysis suggest that the inequality of gas accretion between massive satellite and central galaxies is responsible for the starvation of cluster satellite galaxies that evolve into the massive quenched cluster galaxies observed at z < 0.5.

Automated summary

Gas inflow rates in massive galaxies at z >= 2 are influenced by the environment, with satellite galaxies experiencing a decline in inflow rates upon entering cluster haloes. At z = 2, the gas inflow rate of cluster satellite galaxies is determined by their cluster-centric radii, while the gas inflow rate in centre is determined by the host halo mass. This study suggests that the gas accretion inequality between satellite and central galaxies contributes to the starvation of cluster satellite galaxies.