Morphology Dependence Of Stellar Age in Quenched Galaxies at Redshift ~ 1.2: Massive Compact Galaxies Are Older Than More Extended Ones

Abstract

We report the detection of morphology dependent stellar age in massive quenched galaxies (QGs) at z~1.2. The sense of the dependence is that compact QGs are 0.5-2 Gyr older than normal-sized ones. The evidence comes from three different age indicators, Dn4000, Hdelta and fits to spectral synthesis models, applied to their stacked optical spectra. All age indicators consistently show that the stellar populations of compact QGs are older than their normally-sized counterparts. We detect weak [OII] emission in a fraction of QGs, and the strength of the line, when present, is similar between the two samples; however, compact galaxies exhibit significantly lower frequency of [OII] emission than normal ones. A fraction of both samples are individually detected in 7 Ms Chandra X-ray images (luminosities$\sim 10^{40}$-$10^{41}$ erg/sec). 7 Ms stacks of non-detected galaxies show similarly low luminosities in the soft band only, consistent with a hot gas origin for the X-ray emission. While both [OII] emitters and non-emitters are also X-ray sources among normal galaxies, no compact galaxy with [OII] emission is an X-ray source, arguing against an AGN powering the line in compact galaxies. We interpret the [OII] properties as further evidence that compact galaxies are older and further along into the process of quenching star-formation and suppressing gas accretion. Finally, we argue that the older age of compact QGs is evidence of progenitor bias: compact QGs simply reflect the smaller sizes of galaxies at their earlier quenching epoch, with stellar density most likely having nothing directly to do with cessation of star-formation.

Accepted for publication in ApJ

References in corpus (28)

• Mass and environment as drivers of galaxy evolution in SDSS and zCOSMOS and the origin of the Schechter function
• 3D-HST+CANDELS: The Evolution of the Galaxy Size-Mass Distribution since $z=3$
• Formation of Massive Galaxies at High Redshift: Cold Streams, Clumpy Disks and Compact Spheroids
• Evolutionary Stellar Population Synthesis with MILES. Part I: The Base Models and a New Line Index System
• Compaction and Quenching of High-z Galaxies in Cosmological Simulations: Blue and Red Nuggets
• The Chandra Deep Field-South Survey: 7 Ms Source Catalogs
• Structure and star formation in galaxies out to z=3: evidence for surface density dependent evolution and upsizing
• Absorption Properties and Evolution of Active Galactic Nuclei
• The Formation of Massive, Compact Galaxies at z=2 in the Illustris Simulation
• The Great Observatories Origins Deep Survey. VLT/VIMOS Spectroscopy in the GOODS-South Field
• NICMOS Imaging of DRGs in the HDF-S: A Relation Between Star-Formation and Size at z ~ 2.5
• Charting the evolution of the ages and metallicities of massive galaxies since z=0.7
• Stellar populations from spectroscopy of a large sample of quiescent galaxies at z > 1: Measuring the contribution of progenitor bias to early size growth
• Surface density effects in quenching: cause or effect?
• High-Velocity Outflows Without AGN Feedback: Eddington-Limited Star Formation in Compact Massive Galaxies
• The MASSIVE Survey IV.: The X-ray halos of the most massive early-type galaxies in the nearby Universe
• Early formation of massive, compact, spheroidal galaxies with classical profiles by violent disc instability or mergers
• The Implications of Extreme Outflows from Extreme Starbursts
• The population of early-type galaxies at 1<z<2 - New clues on their formation and evolution
• A Massive Galaxy in its Core Formation Phase Three Billion Years After the Big Bang
• Minor Mergers or Progenitor Bias? The Stellar Ages of Small and Large Quenched Early-Type Galaxies
• Massive Compact Galaxies with High-Velocity Outflows: Morphological Analysis and Constraints on AGN Activity
• The X-ray Properties of Early-Type Galaxies in the Extended Chandra Deep Field-South
• The impact of stellar feedback on hot gas in galaxy haloes: the Sunyaev-Zel'dovich effect and soft X-ray emission
• Low Gas Fractions Connect Compact Star-Forming Galaxies to their z ~ 2 Quiescent Descendants
• The interstellar medium and feedback in the progenitors of the compact passive galaxies at z~2
• Evidence for (and Against) Progenitor Bias in the Size Growth of Compact Red Galaxies
• H-delta in the Integrated Light of Galaxies: What Are We Actually Measuring?

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