The Number Densities and Stellar Populations of Massive Galaxies at 3 < z < 6: A Diverse, Rapidly Forming Population in the Early Universe

Abstract

We present the census of massive (log(M${}_{\ast }$/M${}_{\odot }$)$\ge 11$) galaxies at $3<z<6$ identified over the COSMOS/UltraVISTA Ultra-Deep field stripes: consisting of $\approx 100$ and $\approx 20$ high-confidence candidates at $3<z<4$ and $4<z<6$, respectively. The $3<z<4$ population is comprised of post-starburst, UV star-forming and dusty-star forming galaxies in roughly equal fractions, while UV-star-forming galaxies dominate at $4<z<6$ . We account for various sources of biases in SED modelling, finding that the treatment of emission line contamination is essential for understanding the number densities and mass growth histories of massive galaxies at $z>3$. The significant increase in observed number densities at $z\sim 4$ ($>\times$ 5 in $\lesssim 600$ Myrs) implies that this is the epoch at which log(M${}_{\ast }$/M${}_{\odot }$)$\ge 11$ galaxies emerge in significant numbers, with stellar ages ($\approx 500-900$ Myrs) indicating rapid formation epochs as early as $z\sim 7$. Leveraging ancillary multi-wavelength datasets, we perform panchromatic SED modelling to constrain the total star-formation activity of the sample. The star-formation activity of the sample is generally consistent with being on the star-formation main sequence at the considered redshifts, with $\approx 15-25\%$ of the population showing evidence of suppressed star-formation rates, indicating that quenching mechanisms are already at play by $z\sim 4$. We stack available HST imaging, confirming their compact nature ($r_e\lesssim 2.2$ kpc), consistent with expected sizes of high-$z$ star-forming galaxies. Finally, we discuss how our results are in-line with the early formation epochs and short formation timescales inferred from the fossil records of the most massive galaxies in the Universe.

22 pages, 13 figures, 3 tables (31 pages, 16 figures, 4 tables with Appendix). ApJ submitted. Comments welcome!

References in corpus (60)

• The Cosmic Evolution Survey (COSMOS) -- Overview
• 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 $z=3$
• A simple model to interpret the ultraviolet, optical and infrared emission from galaxies
• An ultra-deep near-infrared spectrum of a compact quiescent galaxy at z=2.2
• Detection of quiescent galaxies in a bicolor sequence from z=0-2
• Cosmic Reionization and Early Star-Forming Galaxies: A Joint Analysis of New Constraints from Planck and Hubble Space Telescope
• Constraining the Low-Mass Slope of the Star Formation Sequence at 0.5<z<2.5
• UltraVISTA: a new ultra-deep near-infrared survey in COSMOS
• An ALMA survey of Sub-millimeter Galaxies in the Extended Chandra Deep Field South: Physical properties derived from ultraviolet-to-radio modelling
• Structure and star formation in galaxies out to z=3: evidence for surface density dependent evolution and upsizing
• The Atlas3D Project - XXX. Star formation histories and stellar population scaling relations of early-type galaxies
• Ages and metallicities of early-type galaxies in the SDSS: new insight into the physical origin of the colour-magnitude and the Mg2-sigmaV relations
• The mass evolution of the first galaxies: stellar mass functions and star formation rates at $4<z<7$ in the CANDELS GOODS-South field
• The galaxy stellar mass function at 3.5<z<7.5 in the CANDELS/UDS, GOODS-South, and HUDF fields
• An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South: High resolution 870um source counts
• 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
• Dust temperature and mid-to-total infrared color distributions for star-forming galaxies at 0<z<4
• Constraining the neutral fraction of hydrogen in the IGM at redshift 7.5
• High-precision Photometric Redshifts from Spitzer/IRAC: Extreme [3.6]-[4.5] Colors Identify Galaxies in the Redshift Range z~6.6-6.9
• Galaxy Stellar Mass Functions from z~10 to z~6 using the Deepest Spitzer/IRAC Data: No Significant Evolution in the Stellar-to-Halo Mass Ratio of Galaxies in the First Gyr of Cosmic Time
• The Assembly Histories of Quiescent Galaxies Since z=0.7 from Absorption Line Spectroscopy
• The Star Formation Epoch of the Most Massive Early-Type Galaxies
• ALMA Observations Show Major Mergers Among the Host Galaxies of Fast-growing, High-redshift Supermassive Black Holes
• A massive, quiescent, population II galaxy at a redshift of 2.1
• A Population of Massive and Evolved Galaxies at z$\ga$5
• A massive, dead disk galaxy in the early Universe
• Evolution of the H$\beta$+[OIII] and [OII] luminosity functions and the [OII] star-formation history of the Universe up to $z$ ~ 5 from HiZELS
• The East Asian Observatory SCUBA--2 survey of the COSMOS field: unveiling 1147 bright sub-millimeter sources across 2.6 square degrees
• Exploring the z=3-4 massive galaxy population with ZFOURGE: the prevalence of dusty and quiescent galaxies
• The Massive Ancient Galaxies At $z>3$ NEar-infrared (MAGAZ3NE) Survey: Confirmation of Extremely Rapid Star-Formation and Quenching Timescales for Massive Galaxies in the Early Universe
• Galaxy And Mass Assembly (GAMA): A forensic SED reconstruction of the cosmic star formation history and metallicity evolution by galaxy type
• MOSFIRE Spectroscopy of Quiescent Galaxies at 1.5 < z < 2.5. I - Evolution of Structural and Dynamical Properties
• An Extremely Massive Quiescent Galaxy at $z=3.493$: Evidence of Insufficiently Rapid Quenching Mechanisms in Theoretical Models
• Automated Mining of the ALMA Archive in the COSMOS Field (A3COSMOS): I. Robust ALMA Continuum Photometry Catalogs and Stellar Mass and Star Formation Properties for ~700 Galaxies at z=0.5-6
• Calibration of [O IV] 26 micron as a Measure of Intrinsic AGN Luminosity
• Determining the stellar masses of submillimetre galaxies: the critical importance of star formation histories
• An ALMA survey of the brightest sub-millimetre sources in the SCUBA-2 COSMOS field
• Timing the earliest quenching events with a robust sample of massive quiescent galaxies at 2 < z < 5
• The Size Evolution of Star-forming Galaxies Since z~7 Using ZFOURGE
• The Evolution of the Fractions of Quiescent and Star-forming Galaxies as a Function of Stellar Mass Since z=3: Increasing Importance of Massive, Dusty Star-forming Galaxies in the Early Universe
• Exploring the evolutionary paths of the most massive galaxies since z~2
• Chasing passive galaxies in the early Universe: a critical analysis in CANDELS GOODS-South
• CLEAR II: Evidence for Early Formation of the Most Compact Quiescent Galaxies at High Redshift
• The mass, colour, and structural evolution of today's massive galaxies since z~5
• Massive and old quiescent galaxies at high redshift
• Spectroscopic Confirmation of an Ultra Massive and Compact Galaxy at z=3.35: A Detailed Look at an Early Progenitor of Local Most Massive Ellipticals
• The Typical Massive Quiescent Galaxy at z$\sim$3 is a Post-starburst
• Exploring AGN and Star Formation Activity of Massive Galaxies at Cosmic Noon
• The Rapid Build-up of Massive Early-type Galaxies. Supersolar Metallicity, High Velocity Dispersion and Young Age for an ETG at z=3.35
• Stellar mass functions of galaxies at 4<z<7 from an IRAC-selected sample in COSMOS/UltraVISTA: limits on the abundance of very massive galaxies
• X-shooter Spectroscopy and HST Imaging of 15 Ultra Massive Quiescent Galaxies at $z\gtrsim 2$
• A Study of Massive and Evolved Galaxies at High Redshift
• Passive galaxies in the early Universe: ALMA confirmation of z~3-5 candidates in the CANDELS GOODS-South field
• On the (Lack of) Evolution of the Stellar Mass Function of Massive Galaxies from $z$=1.5 to 0.4
• Balmer Break Galaxy Candidates at $z\sim 6$: a Potential View on the Star-Formation Activity at $z\gtrsim 14$
• The ALPINE-ALMA [CII] Survey: On the nature of an extremely obscured serendipitous galaxy
• Exploring the High-Mass End of the Stellar Mass Function of Star Forming Galaxies at Cosmic Noon
• Introducing the FLAMINGOS-2 Split-K Medium Band Filters: The Impact on Photometric Selection of High-z Galaxies in the FENIKS-pilot survey

Cited by in corpus (20)

• An Atlas of Color-selected Quiescent Galaxies at $z>3$ in Public $JWST$ Fields
• COSMOS2020: The Galaxy Stellar Mass Function: the assembly and star formation cessation of galaxies at $0.2<z\le 7.5$
• A surprising abundance of massive quiescent galaxies at 3 < z < 5 in the first data from JWST CEERS
• Spectroscopic Confirmation of a Protocluster at $z=3.37$ with a High Fraction of Quiescent Galaxies
• COSMOS2020: Exploring the dawn of quenching for massive galaxies at 3 < z < 5 with a new colour selection method
• The stellar metallicities of massive quiescent galaxies at 1.0 < z < 1.3 from KMOS+VANDELS
• Outshining in the Spatially Resolved Analysis of a Strongly-Lensed Galaxy at z=6.072 with JWST NIRCam
• Beyond UVJ: Color Selection of Galaxies in the JWST Era
• Probing cold gas in a massive, compact star-forming galaxy at z=6
• Missing Giants: Predictions on Dust-Obscured Galaxy Stellar Mass Assembly Throughout Cosmic Time
• The GOGREEN Survey: Constraining the Satellite Quenching Timescale in Massive Clusters at $\mathbf{z}\gtrsim 1$
• Early results from GLASS-JWST XV: properties of the faintest red sources in the NIRCAM deep fields
• 3D-DASH: The Widest Near-Infrared Hubble Space Telescope Survey
• No Need for Extreme Stellar Masses at z~7: A Test-case Study of COS-87259
• MAGAZ3NE: Massive, Extremely Dusty Galaxies at $z\sim 2$ Lead to Photometric Overestimation of Number Densities of the Most Massive Galaxies at $3<z<4$
• Probing the earliest phases in the formation of massive galaxies with simulated HST+JWST imaging data from Illustris
• COOL-LAMPS IV: A Sample of Bright Strongly-Lensed Galaxies at $3<z<4$
• Strength in Numbers: Red Galaxies Bolster the Cosmic Star Formation Rate Density at z > 3
• Merging history of massive galaxies at 3<z<6
• Simulating continuum-based redshift measurement in the \textit{Roman's} High Latitude Spectroscopy Survey