Color gradients along the quiescent galaxy sequence: clues to quenching and structural growth

Abstract

This Letter examines how the sizes, structures, and color gradients of galaxies change along the quiescent sequence. Our sample consists of ~400 quiescent galaxies at $1.0\le z\le 2.5$ and $10.1\le \log M_{\ast }/M_{\odot }\le 11.6$ in three CANDELS fields. We exploit deep multi-band HST imaging to derive accurate mass profiles and color gradients, then use an empirical calibration from rest-frame UVJ colors to estimate galaxy ages. We find that -- contrary to previous results -- the youngest quiescent galaxies are not significantly smaller than older quiescent galaxies at fixed stellar mass. These `post-starburst' galaxies only appear smaller in half-light radii because they have systematically flatter color gradients. The strength of color gradients in quiescent galaxies is a clear function of age, with older galaxies exhibiting stronger negative color gradients (i.e., redder centers). Furthermore, we find that the central mass surface density ${\Sigma }_1$ is independent of age at fixed stellar mass, and only weakly depends on redshift. This finding implies that the central mass profiles of quiescent galaxies do not significantly change with age; however, we find that older quiescent galaxies have additional mass at large radii. Our results support the idea that building a massive core is a necessary requirement for quenching beyond $z=1$, and indicate that post-starburst galaxies are the result of a rapid quenching process that requires structural change. Furthermore, our observed color gradient and mass profile evolution supports a scenario where quiescent galaxies grow inside-out via minor mergers.

7 pages, 5 figures. Accepted to ApJL

References in corpus (17)

• 3D-HST+CANDELS: The Evolution of the Galaxy Size-Mass Distribution since $z=3$
• Compaction and Quenching of High-z Galaxies in Cosmological Simulations: Blue and Red Nuggets
• Evidence for Mature Bulges and an Inside-out Quenching Phase 3 Billion Years After the Big Bang
• The FourStar Galaxy Evolution Survey (ZFOURGE): ultraviolet to far-infrared catalogs, medium-bandwidth photometric redshifts with improved accuracy, stellar masses, and confirmation of quiescent galaxies to z~3.5
• Sub-kpc ALMA imaging of compact star-forming galaxies at z~2.5: revealing the formation of dense galactic cores in the progenitors of compact quiescent galaxies
• The evolution of post-starburst galaxies from z=2 to z= 0.5
• Stellar populations from spectroscopy of a large sample of quiescent galaxies at z > 1: Measuring the contribution of progenitor bias to early size growth
• 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
• Dense cores in galaxies out to z=2.5 in SDSS, UltraVISTA, and the five 3D-HST/CANDELS fields
• Predicting Quiescence: The Dependence of Specific Star Formation Rate on Galaxy Size and Central Density at 0.5<z<2.5
• Connection Between Stellar Mass Distributions Within Galaxies and Quenching Since z =2
• Half-mass radii of quiescent and star-forming galaxies evolve slowly from 0 < z < 2.5: implications for galaxy assembly histories
• CLEAR II: Evidence for Early Formation of the Most Compact Quiescent Galaxies at High Redshift
• The colors and sizes of recently quenched galaxies: a result of compact starburst before quenching
• Cluster and field elliptical galaxies at z~1.3. The marginal role of the environment and the relevance of the galaxy central regions
• On the evolution of the central density of quiescent galaxies
• LEO-Py: Estimating likelihoods for correlated, censored, and uncertain data with given marginal distributions

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