Red Nuggets at High Redshift: Structural Evolution of Quiescent Galaxies Over 10 Gyr of Cosmic History

TL;DR

This study analyzes the continuous size growth of quiescent early-type galaxies over 10 billion years, finding a consistent evolution pattern that aligns with recent models and UV-bright galaxy observations.

Contribution

It provides a homogeneous synthesis of 17 surveys and new data, demonstrating a continuous, mass-independent size evolution of quiescent galaxies over a broad redshift range.

Findings

Size growth is gradual and continuous from z~2.7 to 0.2.

Size evolution follows R_e (1+z)^(-1.62 +/- 0.34).

Results agree with recent theoretical models and UV-bright galaxy evolution.

Abstract

We present an analysis of the size growth seen in early-type galaxies over 10 Gyr of cosmic time. Our analysis is based on a homogeneous synthesis of published data from 17 spectroscopic surveys observed at similar spatial resolution, augmented by new measurements for galaxies in the Gemini Deep Deep Survey. In total, our sample contains structural data for 465 galaxies (mainly early-type) in the redshift range 0.2<z<2.7. The size evolution of passively-evolving galaxies over this redshift range is gradual and continuous, with no evidence for an end or change to the process around z~1, as has been hinted at by some surveys which analyze subsets of the data in isolation. The size growth appears to be independent of stellar mass, with the mass-normalized half-light radius scaling with redshift as R_e (1+z)^(-1.62 +/- 0.34). Surprisingly, this power law seems to be in good agreement with the recently reported continuous size evolution of UV-bright galaxies in the redshift range z~0.5-3.5. It is also in accordance with the predictions from recent theoretical models.