A galaxy group candidate at z~3.7 in the COSMOS field

Abstract

We report a galaxy group candidate HPC1001 at $z\approx 3.7$ in the COSMOS field. This structure was selected as a high galaxy overdensity at $z>3$ in the COSMOS2020 catalog. It contains ten candidate members, of which eight are assembled in a $10^{\prime \prime }\times 10^{\prime \prime }$ area with the highest sky density among known protoclusters and groups at $z>3$. Four out of ten sources were also detected at 1.2 mm with Atacama Large Millimeter Array continuum observations. Photometric redshifts, measured by four independent methods, fall within a narrow range of $3.5<z<3.9$ and with a weighted average of $z=3.65\pm 0.07$. The integrated far-IR-to-radio spectral energy distribution yields a total UV and IR star formation rate $\mathrm{SFR}\approx 900M_{\odot }y{r}^{-1}$. We also estimated a halo mass of $\sim 10^{13}{M}_{\odot }$ for the structure, which at this redshift is consistent with potential cold gas inflow. Remarkably, the most massive member has a specific star formation rate and dust to stellar mass ratio of $M_{\mathrm{dust}}/M_{\ast }$ that are both significantly lower than that of star-forming galaxies at this redshift, suggesting that HPC1001 could be a $z\approx 3.7$ galaxy group in maturing phase. If confirmed, this would be the earliest structure in maturing phase to date, and an ideal laboratory to study the formation of the earliest quiescent galaxies as well as cold gas accretion in dense environments.

arXiv commentA&A Letter in press

References in corpus (49)

• Galactic Stellar and Substellar Initial Mass Function
• The Average Star Formation Histories of Galaxies in Dark Matter Halos from z=0-8
• EAZY: A Fast, Public Photometric Redshift Code
• Accurate photometric redshifts for the CFHT Legacy Survey calibrated using the VIMOS VLT Deep Survey
• The COSMOS2015 Catalog: Exploring the 1<z<6 Universe with half a million galaxies
• The Large Scale Bias of Dark Matter Halos: Numerical Calibration and Model Tests
• The Evolution of the Stellar Mass Functions of Star-Forming and Quiescent Galaxies to z = 4 from the COSMOS/UltraVISTA Survey
• The Herschel view of the dominant mode of galaxy growth from z=4 to the present day
• The Evolving Interstellar Medium of Star Forming Galaxies Since z=2 as Probed by Their Infrared Spectral Energy Distributions
• COSMOS2020: A panchromatic view of the Universe to $z\sim 10$ from two complementary catalogs
• The Evolution of the Star-forming Interstellar Medium across Cosmic Time
• The deepest Herschel-PACS far-infrared survey: number counts and infrared luminosity functions from combined PEP/GOODS-H observations
• Two bright submillimeter galaxies in a z=4.05 proto-cluster in GOODS-North, and accurate radio-infrared photometric redshifts
• The realm of the galaxy protoclusters
• Toy Models for Galaxy Formation versus Simulations
• A massive proto-cluster of galaxies at a redshift of z {\approx} 5.3
• The Intense Starburst HDF850.1 in a Galaxy Overdensity at z=5.2 in the Hubble Deep Field
• Discovery of a galaxy cluster with a violently starbursting core at z=2.506
• 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
• An extreme proto-cluster of luminous dusty starbursts in the early Universe
• "Super-deblended" Dust Emission in Galaxies: II. Far-IR to (sub)millimeter photometry and high redshift galaxy candidates in the full COSMOS field
• An excess of dusty starbursts related to the Spiderweb galaxy
• Core creation in galaxies and haloes via sinking massive objects
• The progeny of a Cosmic Titan: a massive multi-component proto-supercluster in formation at z=2.45 in VUDS
• Massive starburst galaxies in a z=2.16 proto-cluster unveiled by panoramic H-alpha mapping
• The East Asian Observatory SCUBA--2 survey of the COSMOS field: unveiling 1147 bright sub-millimeter sources across 2.6 square degrees
• Discovery of four apparently cold dusty galaxies at z=3.62-5.85 in the COSMOS field: direct evidence of CMB impact on high-redshift galaxy observables
• The unexpectedly large dust and gas content of quiescent galaxies at z>1.4
• Rise of the Titans: A Dusty, Hyper-Luminous "870 micron Riser" Galaxy at z~6
• COSMOS2020: The cosmic evolution of the stellar-to-halo mass relation for central and satellite galaxies up to z~5
• Three Lyman-alpha emitting filaments converging to a massive galaxy group at z=2.91: discussing the case for cold gas infall
• Chandra centres for COSMOS X-ray galaxy groups: Differences in stellar properties between central dominant and offset brightest group galaxies
• A Census of Stellar Mass in 10 Massive Haloes at z~1 from the GCLASS Survey
• MAHALO Deep Cluster Survey II. Characterizing massive forming galaxies in the Spiderweb protocluster at z=2.2
• Deceptively cold dust in the massive starburst galaxy GN20 at $z\sim 4$
• Confirming Herschel candidate protoclusters from ALMA/VLA CO observations
• Spectroscopic confirmation of a mature galaxy cluster at redshift two
• The Interstellar Medium of Quiescent Galaxies and its Evolution With Time
• Evidence for Cold-stream to Hot-accretion Transition as Traced by Lyα Emission from Groups and Clusters at 2 < z < 3.3
• COALAS: I. ATCA CO(1-0) survey and luminosity function in the Spiderweb protocluster at z=2.16
• The Evolving Interstellar Medium of Star-Forming Galaxies, as traced by $\text{Stardust}$
• Predicted future fate of COSMOS galaxy protoclusters over 11 Gyr with constrained simulations
• Radio selection of the most distant galaxy clusters
• An ancient massive quiescent galaxy found in a gas-rich z ~ 3 group
• Towards a census of high-redshift dusty galaxies with $Herschel$: A selection of "500 $\mu$m-risers"
• Early Science with the Large Millimeter Telescope: Constraining the Gas Fraction of a Compact Quiescent Galaxy at z=1.883
• Optimizing high redshift galaxy surveys for environmental information
• The Nature of 500 Micron Risers II: Sub-mm Faint Dusty Star Forming Galaxies

Cited by in corpus (8)

• COSMOS2020: Discovery of a protocluster of massive quiescent galaxies at $z=2.77$
• Cosmic Vine: A z=3.44 large-scale structure hosting massive quiescent galaxies
• $JWST$ Insight Into a Lensed $HST$-dark Galaxy and its Quiescent Companion at $z=2.58$
• Massive galaxy formation caught in action at z~5 with JWST
• NOEMA formIng Cluster survEy (NICE): Characterizing eight massive galaxy groups at $1.5<z<4$ in the COSMOS field
• Revealing the hidden cosmic feast: A z=4.3 galaxy group hosting two optically dark, efficiently star-forming galaxies
• Cosmic Vine: High abundance of massive galaxies and dark matter halos in a forming cluster at z=3.44
• Noema formIng Cluster survEy (NICE): A Census of Star Formation and Cold Gas Properties in Massive protoclusters at 1.5<z<4