The UV Luminosity Function of Protocluster Galaxies at $z\sim 4$: the Bright-end Excess and the Enhanced Star Formation Rate Density

Abstract

We report the rest-frame ultraviolet luminosity function of $g$-dropout galaxies in 177 protocluster candidates (PC UVLF) at $z\sim 4$ selected in the Hyper Suprime-Cam Subaru Strategic Program. Comparing with the UVLF of field galaxies at the same redshift, we find that the PC UVLF shows a significant excess towards the bright-end. This excess can not be explained by the contribution of only active galactic nuclei, and we also find that this is more significant in higher dense regions. Assuming that all protocluster members are located on the star formation main sequence, the PC UVLF can be converted into a stellar mass function. Consequently, our protocluster members are inferred to have a 2.8 times more massive characteristic stellar mass than that of the field Lyman break galaxies at the same redshift. This study, for the first time, clearly shows that the enhancement in star formation or stellar mass in overdense regions can generally be seen as early as at $z\sim 4$. We also estimate the star formation rate density (SFRD) in protocluster regions as $\simeq 6-20\%$ of the cosmic SFRD, based on the measured PC UVLF after correcting for the selection incompleteness in our protocluster sample. This high value suggests that protoclusters make a non-negligible contribution to the cosmic SFRD at $z\sim 4$, as previously suggested by simulations. Our results suggest that protoclusters are essential components for the galaxy evolution at $z\sim 4$.

arXiv comment22 pages, 16 figures, Accepted for publication in ApJ

References in corpus (102)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Stellar population synthesis at the resolution of 2003
• Star Formation in Galaxies Along the Hubble Sequence
• The Dust Content and Opacity of Actively Star-Forming Galaxies
• Cosmic Star Formation History
• LSST: from Science Drivers to Reference Design and Anticipated Data Products
• The Eleventh and Twelfth Data Releases of the Sloan Digital Sky Survey: Final Data from SDSS-III
• The epochs of early-type galaxy formation as a function of environment
• A Highly Consistent Framework for the Evolution of the Star-Forming "Main Sequence" from z~0-6
• CIGALE: a python Code Investigating GALaxy Emission
• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• Dust Absorption And The Ultraviolet Luminosity Density At z \approx 3 As Calibrated By Local Starburst Galaxies
• The Hyper Suprime-Cam SSP Survey: Overview and Survey Design
• Mass assembly in quiescent and star-forming galaxies since z=4 from UltraVISTA
• The Galactic disk mass function: reconciliation of the HST and nearby determinations
• The Evolution of the Galaxy Rest-Frame Ultraviolet Luminosity Function Over the First Two Billion Years
• Galaxy formation in the Planck Cosmology - I. Matching the observed evolution of star formation rates, colours and stellar masses
• First Data Release of the Hyper Suprime-Cam Subaru Strategic Program
• Galaxy Zoo: the dependence of morphology and colour on environment
• A Large Structure of Galaxies At Redshift z~3 and its Cosmological Implications
• The Hyper Suprime-Cam Software Pipeline
• UV-continuum slopes at z~4-7 from the HUDF09+ERS+CANDELS observations: Discovery of a well-defined UV-color magnitude relationship for z>=4 star-forming galaxies
• UV Continuum Slope and Dust Obscuration from z~6 to z~2: The Star Formation Rate Density at High Redshift
• UV-Continuum Slopes of >4000 z~4-8 Galaxies from the HUDF/XDF, HUDF09, ERS, CANDELS-South, and CANDELS-North Fields
• Ancient Light from Young Cosmic Cities: Physical and Observational Signatures of Galaxy Proto-Clusters
• The Evolution of the Galaxy Stellar Mass Function at z= 4-8: A Steepening Low-mass-end Slope with Increasing Redshift
• Galaxy formation in WMAP1 and WMAP7 cosmologies
• The realm of the galaxy protoclusters
• The SFR-M* Relation and Empirical Star-Formation Histories from ZFOURGE at 0.5 < z < 4
• The Star Formation Rate Density and Dust Attenuation Evolution over 12 Gyr with the VVDS Surveys
• The Dependence of Cluster Galaxy Star Formation Rates on the Global Environment
• The VIMOS Public Extragalactic Survey (VIPERS): First Data Release of 57 204 spectroscopic measurements
• A dominant population of optically invisible massive galaxies in the early Universe
• Galaxy growth in a massive halo in the first billion years of cosmic history
• Discovery of a galaxy cluster with a violently starbursting core at z=2.506
• The Discovery of Primeval Large-Scale Structures with Forming Clusters at Redshift 6
• Galaxy Protoclusters as Drivers of Cosmic Star-Formation History in the First 2 Gyr
• A massive core for a cluster of galaxies at a redshift of 4.3
• A lack of evolution in the very bright-end of the galaxy luminosity function from z = 8-10
• Great Optically Luminous Dropout Research Using Subaru HSC (GOLDRUSH). I. UV Luminosity Functions at $z\sim 4-7$ Derived with the Half-Million Dropouts on the 100 deg${}^2$ Sky
• Quiescent galaxies 1.5 billion years after the Big Bang and their progenitors
• The most distant structure of galaxies known: a protocluster at z=4.1
• WINGS: a WIde-field Nearby Galaxy-cluster Survey. I - Optical imaging
• Spectroscopic Confirmation of the Rich z=1.80 Galaxy Cluster JKCS 041 Using the WFC3 Grism: Environmental Trends in the Ages and Structure of Quiescent Galaxies
• What are Protoclusters? -- Defining High Redshift Galaxy Clusters and Protoclusters
• The galaxy luminosity function at z ~ 6 and evidence for rapid evolution in the bright end from z ~ 7 to 5
• Spectroscopic Identification of a Proto-Cluster at z=2.300: Environmental Dependence of Galaxy Properties at High Redshift
• Evidence for Significant Growth in the Stellar Mass of Brightest Cluster Galaxies over the Past 10 Billion Years
• An optically-selected cluster catalog at redshift 0.1<z<1.1 from the Hyper Suprime-Cam Subaru Strategic Program S16A data
• Spectroscopic Confirmation of a Massive Red-Sequence-Selected Galaxy Cluster at z = 1.34 in the SpARCS-South Cluster Survey
• Spectroscopic Confirmation of Two Massive Red-Sequence-Selected Galaxy Clusters at z ~ 1.2 in the SpARCS-North Cluster Survey
• The UV galaxy luminosity function at z=3-5 from the CFHT Legacy Survey Deep fields
• Colour corrections for high redshift objects due to intergalactic attenuation
• The environmental dependence of the stellar mass function at z~1: Comparing cluster and field between the GCLASS and UltraVISTA surveys
• Lyman break galaxies, Lya emitters and a radio galaxy in a protocluster at z=4.1
• Massive starburst galaxies in a z=2.16 proto-cluster unveiled by panoramic H-alpha mapping
• Bright and Faint Ends of Ly$\alpha$ Luminosity Functions at $\text{z}=2$ Determined by the Subaru Survey: Implications for AGN, Magnification Bias, and ISM HI Evolution
• H-alpha emitters in z~2 proto-clusters: evidence for faster evolution in dense environments
• The Chandra Deep Protocluster Survey: Evidence for an Enhancement in the AGN Activity in the SSA22 Protocluster at z = 3.09
• GOLDRUSH. III. A Systematic Search of Protoclusters at $z\sim 4$ Based on the $>100\mathrm{de}{\mathrm{g}}^2$ Area
• The Quasar Luminosity Function at Redshift 4 with Hyper Suprime-Cam Wide Survey
• The VIMOS Ultra Deep Survey: Emerging from the Dark, a Massive Proto-Cluster at z~4.57
• Discovery of a rich proto-cluster at z=2.9 and associated diffuse cold gas in the VIMOS Ultra-Deep Survey (VUDS)
• A star-bursting proto-cluster in making associated to a radio galaxy at z=2.53 discovered by H_alpha imaging
• No galaxy left behind: accurate measurements with the faintest objects in the Dark Energy Survey
• The Environmental Dependence of the Infrared Luminosity and Stellar Mass Functions
• Stellar mass function of cluster galaxies at z $\sim$ 1.5: evidence for reduced quenching efficiency at high redshift
• A Systematic Survey of Protoclusters at $z\sim 3-6$ in the CFHTLS Deep Fields
• Discovery of a protocluster at z~6
• Stellar Velocity Dispersion of a Massive Quenching Galaxy at z=4.01
• Discovery of a large number of candidate proto-clusters traced by ~15 Mpc-scale galaxy overdensities in COSMOS
• MAHALO Deep Cluster Survey I. Accelerated and enhanced galaxy formation in the densest regions of a protocluster at z=2.5
• Shadow of a Colossus: A z=2.45 Galaxy Protocluster Detected in 3D Ly-a Forest Tomographic Mapping of the COSMOS Field
• The concentration-mass relation of clusters of galaxies from the OmegaWINGS survey
• MApping the Most Massive Overdensities Through Hydrogen (MAMMOTH) I: Methodology
• SILVERRUSH. VII. Subaru/HSC Identifications of 42 Protocluster Candidates at z~6-7 with the Spectroscopic Redshifts up to z=6.574: Implications for Cosmic Reionization
• The 10k zCOSMOS: morphological transformation of galaxies in the group environment since z~1
• Spectroscopic Confirmation of Three Red-Sequence Selected Galaxy Clusters at z=0.87, 1.16 and 1.21 from the SpARCS Survey
• The galaxy stellar mass function and its evolution with time show no dependence on global environment
• A z=2.5 protocluster associated with the radio galaxy MRC 2104-242: star formation and differing mass functions in dense environments
• Observational Requirements for Lyman-alpha Forest Tomographic Mapping of Large-Scale Structure at z ~ 2
• Luminous Quasars Do Not Live in the Most Overdense Regions of Galaxies at z~4
• Characterising and Identifying Galaxy Protoclusters
• A Giant Protocluster of Galaxies at Redshift 5.7
• Glimpsing the Imprint of Local Environment on the Galaxy Stellar Mass Function
• The stellar mass function of galaxies in Planck-selected clusters at 0.5 < z < 0.7: new constraints on the timescale and location of satellite quenching
• Luminosity Functions of Lyman-Break Galaxies at z~4 and 5 in the Subaru Deep Field
• The rest-frame UV luminosity function at $z\simeq 4$: a significant contribution of AGN to the bright-end of the galaxy population
• Enhancement of AGN in a protocluster at z=1.6
• First results on the cluster galaxy population from the Subaru Hyper Suprime-Cam survey. III. Brightest cluster galaxies, stellar mass distribution, and active galaxies
• How Do Galaxies trace a large scale structure?: A case study around a massive protocluster at $z=3.13$
• The Fraction of Active Galactic Nuclei in the USS 1558-003 Protocluster at z = 2.53
• The impact of global environment on galaxy mass functions at low redshift
• The formation history of massive cluster galaxies as revealed by CARLA
• Enhancement of Galaxy Overdensity around Quasar Pairs at z<3.6 based on the Hyper Suprime-Cam Subaru Strategic Program Survey
• Voids in Lyα Forest Tomographic Maps
• Planck far-infrared detection of Hyper Suprime-Cam protoclusters at $\mathbf{z}\sim 4$: hidden AGN and star formation activity
• A census of galaxy constituents in a Coma Progenitor observed at z>3
• The HectoMAP Cluster Survey - I. redMaPPer Clusters
• Discovery of Protoclusters at z~3.7 & 4.9: Embedded in Primordial Superclusters
• The brightest UV-selected galaxies in protoclusters at $z\sim 4$: Ancestors of Brightest Cluster Galaxies?
• The environments of Ly$\alpha$ blobs I: Wide-field Ly$\alpha$ imaging of TN J1338-1942, a powerful radio galaxy at $z\simeq 4.1$ associated with a giant Ly$\alpha$ nebula

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• A${}^3$COSMOS: A census on the molecular gas mass and extent of main-sequence galaxies across cosmic time
• Accelerated galaxy growth and environmental quenching in a protocluster at z=3.24
• Interrelation of the environment of Ly$\alpha$ emitters and massive galaxies at $2<z<4.5$
• The UV luminosity function at 0.6 < z < 1 from UVCANDELS
• A systematic search for galaxy protocluster cores at the transition epoch of their star formation activity
• The environments and hosts of metal absorption at z>5
• Connecting the growth of galaxies to the large-scale environment in a massive node of the Cosmic Web at z~3
• Cluster candidates with massive quiescent galaxies at $z\sim 2$
• Galaxy populations in protoclusters at cosmic noon
• Lyman Alpha line properties at $z\simeq 3.78$ and their environmental dependence: a case study around a massive proto-cluster
• A massive quiescent galaxy confirmed in a protocluster at z=3.09
• Brighter and More Massive Galaxies in the Vicinity of Lyman-alpha Nebulae
• First Light And Reionisation Epoch Simulations (FLARES) III: The properties of massive dusty galaxies at cosmic dawn