Tightly coupled morpho-kinematic evolution for massive star-forming and quiescent galaxies across 7 Gyr of cosmic time

TL;DR

This study uses the Fundamental Plane to analyze the evolution of massive galaxies over 7 billion years, revealing stable mass relations across star-forming and quiescent types and minimal structural change since redshift 1.

Contribution

It demonstrates that star-forming and quiescent massive galaxies follow a stable mass Fundamental Plane from redshift 0 to 1, highlighting minimal structural evolution and the utility of the FP in galaxy evolution studies.

Findings

Star-forming and quiescent galaxies lie on the same mass FP across 0<z<1.

Evolution in $M_{dyn}/L_g$ is driven by stellar population changes.

Galaxy size and mass growth occur within the mass FP constraints.

Abstract

We use the Fundamental Plane (FP) to measure the redshift evolution of the dynamical mass-to-light ratio ($M_{\mathrm{dyn}}/L$) and the dynamical-to-stellar mass ratio ($M_{\mathrm{dyn}}/M_*$). Although conventionally used to study the properties of early-type galaxies, we here obtain stellar kinematic measurements from the Large Early Galaxy Astrophysics Census (LEGA-C) Survey for a sample of $\sim1400$ massive ($\log( M_*/M_\odot) >10.5$) galaxies at $0.6<z<1.0$ that span a wide range in star formation activity. In line with previous studies, we find a strong evolution in $M_{\mathrm{dyn}}/L_g$ with redshift. In contrast, we find only a weak dependence of the mean value of $M_{\mathrm{dyn}}/M_*$ on the specific star formation rate, and a redshift evolution that likely is explained by systematics. Therefore, we demonstrate that star-forming and quiescent galaxies lie on the same, stable mass FP across $0<z<1$, and that the decrease in $M_{\mathrm{dyn}}/L_g$ toward high redshift can be attributed entirely to evolution of the stellar populations. Moreover, we show that the growth of galaxies in size and mass is constrained to occur within the mass FP. Our results imply either minimal structural evolution in massive galaxies since $z\sim1$, or a tight coupling in the evolution of their morphological and dynamical properties, and establish the mass FP as a tool for studying galaxy evolution with low impact from progenitor bias.