Revealing Impact of Critical Stellar Central Density on Galaxy Quenching through Cosmic Time

Abstract

In the previous work of Xu & Peng (2021), we investigated the structural and environmental dependence on quenching in the nearby universe. In this work we extend our investigations to higher redshifts by combining galaxies from SDSS and ZFOURGE surveys. In low density, we find a characteristic $Σ_{1\ kpc}$ above which the quenching is initiated as indicated by their population-averaged color. $Σ^{crit}_{1\ kpc}$ shows only weakly mass-dependency at all redshifts, which suggests that the internal quenching process is more related to the physics that acts in the central region of galaxies. In high density, $Σ^{crit}_{1\ kpc}$ for galaxies at $z > 1$ is almost indistinguishable with their low-density counterparts. At $z < 1$, $Σ^{crit}_{1\ kpc}$ for low-mass galaxies becomes progressively strongly mass-dependent, which is due to the increasingly stronger environmental effects at lower redshifts. $Σ^{crit}_{1\ kpc}$ in low density shows strong redshift evolution with $\sim 1$ dex decrement from $z = 2.5$ to $z = 0$. It is likely due to that at a given stellar mass, the host halo is on average more massive and gas-rich at higher redshifts, hence a higher level of integrated energy from more massive black hole is required to quench. As the halo evolves from cold to hot accretion phase at lower redshifts, the gas is shock-heated and becomes more vulnerable to AGN feedback processes, as predicted by theory. Meanwhile, angular momentum quenching also becomes more effective at low redshifts, which complements a lower level of integrated energy from black hole to quench.