Stellar populations from spectroscopy of a large sample of quiescent galaxies at z > 1: Measuring the contribution of progenitor bias to early size growth

Abstract

We analyze the stellar populations of a sample of 62 massive (log Mstar/Msun > 10.7) galaxies in the redshift range 1 < z < 1.6, with the main goal of investigating the role of recent quenching in the size growth of quiescent galaxies. We demonstrate that our sample is not biased toward bright, compact, or young galaxies, and thus is representative of the overall quiescent population. Our high signal-to-noise ratio Keck LRIS spectra probe the rest-frame Balmer break region which contains important absorption line diagnostics of recent star formation activity. We obtain improved measures of the various stellar population parameters, including the star-formation timescale tau, age and dust extinction, by fitting templates jointly to both our spectroscopic and broad-band photometric data. We identify which quiescent galaxies were recently quenched and backtrack their individual evolving trajectories on the UVJ color-color plane finding evidence for two distinct quenching routes. By using sizes measured in the previous paper of this series, we confirm that the largest galaxies are indeed among the youngest at a given redshift. This is consistent with some contribution to the apparent growth from recent arrivals, an effect often called progenitor bias. However, we calculate that recently-quenched objects can only be responsible for about half the increase in average size of quiescent galaxies over a 1.5 Gyr period, corresponding to the redshift interval 1.25 < z < 2. The remainder of the observed size evolution arises from a genuine growth of long-standing quiescent galaxies.

Accepted for publication in the Astrophysical Journal, 14 pages, 11 figures

References in corpus (13)

• EAZY: A Fast, Public Photometric Redshift Code
• A Highly Consistent Framework for the Evolution of the Star-Forming "Main Sequence" from z~0-6
• 3D-HST+CANDELS: The Evolution of the Galaxy Size-Mass Distribution since $z=3$
• An ultra-deep near-infrared spectrum of a compact quiescent galaxy at z=2.2
• 3D-HST WFC3-selected Photometric Catalogs in the Five CANDELS/3D-HST Fields: Photometry, Photometric Redshifts and Stellar Masses
• Detection of quiescent galaxies in a bicolor sequence from z=0-2
• What do we learn from IRAC observations of galaxies at 2 < z < 3.5?
• The Multiwavelength Survey by Yale-Chile (MUSYC): Deep Medium-Band optical imaging and high quality 32-band photometric redshifts in the ECDF-S
• The Detection of a Red Sequence of Massive Field Galaxies at z~2.3 and its Evolution to z~0
• Ages and Abundances of Red Sequence Galaxies as a Function of LINER Emission Line Strength
• From Starburst to Quiescence: Testing AGN feedback in Rapidly Quenching Post-Starburst Galaxies
• A Massive Galaxy in its Core Formation Phase Three Billion Years After the Big Bang
• MOSFIRE Absorption Line Spectroscopy of z > 2 Quiescent Galaxies: Probing a Period of Rapid Size Growth

Cited by in corpus (31)

• The Formation of Massive, Compact Galaxies at z=2 in the Illustris Simulation
• Half-mass radii for ~7,000 galaxies at 1.0 < z < 2.5: most of the evolution in the mass-size relation is due to color gradients
• Predicting Quiescence: The Dependence of Specific Star Formation Rate on Galaxy Size and Central Density at 0.5<z<2.5
• Bulge-forming galaxies with an extended rotating disk at z~2
• How to quench a galaxy
• MOSFIRE Spectroscopy of Quiescent Galaxies at 1.5 < z < 2.5. I - Evolution of Structural and Dynamical Properties
• Connection Between Stellar Mass Distributions Within Galaxies and Quenching Since z =2
• Hiding in plain sight: An abundance of compact massive spheroids in the local Universe
• Minor Mergers or Progenitor Bias? The Stellar Ages of Small and Large Quenched Early-Type Galaxies
• Half-mass radii of quiescent and star-forming galaxies evolve slowly from 0 < z < 2.5: implications for galaxy assembly histories
• An ALMA survey of submillimetre galaxies in the COSMOS field: Physical properties derived from energy balance spectral energy distribution modelling
• The quenching of galaxies, bulges, and disks since cosmic noon: A machine learning approach for identifying causality in astronomical data
• ALMA measures rapidly depleted molecular gas reservoirs in massive quiescent galaxies at z~1.5
• The mass, colour, and structural evolution of today's massive galaxies since z~5
• The GOGREEN survey: Post-infall environmental quenching fails to predict the observed age difference between quiescent field and cluster galaxies at z>1
• Color gradients along the quiescent galaxy sequence: clues to quenching and structural growth
• The colors and sizes of recently quenched galaxies: a result of compact starburst before quenching
• Galaxy Sizes Since $z=2$ from the Perspective of Stellar Mass Distribution within Galaxies
• First results from the VIRIAL survey: the stellar content of $UVJ$-selected quiescent galaxies at $1.5<z<2$ from KMOS
• The KMOS Cluster Survey (KCS) I: The fundamental plane and the formation ages of cluster galaxies at redshift $1.4<z<1.6$
• Time Evolution of Galaxy Scaling Relations in Cosmological Simulations
• The kinematics of massive quiescent galaxies at $1.4<z<2.1$: dark matter fractions, IMF variation, and the relation to local early-type galaxies
• A combined VANDELS and LEGA-C study: the evolution of quiescent galaxy size, stellar mass and age from $\text{z}=0.6$ to $\text{z}=1.3$
• Compact, bulge dominated structures of spectroscopically confirmed quiescent galaxies at z~3
• Towards an Understanding of the Massive Red Spiral Galaxy Formation
• Mapping Accreted Stars in Early-Type Galaxies Across the Mass-Size Plane
• The Complete Local Volume Groups Sample -- IV. Star formation and gas content in group-dominant galaxies
• Implications of Increased Central Mass Surface Densities for the Quenching of Low-mass Galaxies
• The differences between mass- and light-derived structural parameters over time for MaNGA Elliptical galaxies
• The ages, metallicities and element abundance ratios of massive quenched galaxies at z~1.6
• A massive quiescent galaxy confirmed in a protocluster at z=3.09