MAGAZ3NE: Massive, Extremely Dusty Galaxies at $z\sim 2$ Lead to Photometric Overestimation of Number Densities of the Most Massive Galaxies at $3<z<4$

Abstract

We present rest-frame optical spectra from Keck/MOSFIRE and Keck/NIRES of 16 candidate ultramassive galaxies targeted as part of the Massive Ancient Galaxies at $z>3$ Near-Infrared (MAGAZ3NE) Survey. These candidates were selected to have photometric redshifts $3\lesssim z_{\mathrm{phot}}<4$, photometric stellar masses log($M$/M${}_{\odot }$)$>11.7$, and well-sampled photometric spectral energy distributions (SEDs) from the UltraVISTA and VIDEO surveys. In contrast to previous spectroscopic observations of blue star-forming and post-starburst ultramassive galaxies, candidates in this sample have very red SEDs implying significant dust attenuation, old stellar ages, and/or active galactic nuclei (AGN). Of these galaxies, eight are revealed to be heavily dust-obscured $2.0<z<2.7$ galaxies with strong emission lines, some showing broad features indicative of AGN, three are Type I AGN hosts at $z>3$, one is a $z\sim 1.2$ dusty galaxy, and four galaxies do not have a confirmed spectroscopic redshift. In fact, none of the sample has |$z_{\mathrm{spec}}-z_{\mathrm{phot}}$|$<0.5$, suggesting difficulties for photometric redshift programs in fitting similarly red SEDs. The prevalence of these red interloper galaxies suggests that the number densities of high-mass galaxies are overestimated at $z\gtrsim 3$ in large photometric surveys, helping to resolve the `impossibly early galaxy problem' and leading to much better agreement with cosmological galaxy simulations. A more complete spectroscopic survey of ultramassive galaxies is required to pin down the uncertainties on their number densities in the early universe.

Accepted for publication in ApJ

References in corpus (48)

• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• The Cosmic Evolution Survey (COSMOS) -- Overview
• EAZY: A Fast, Public Photometric Redshift Code
• An ultra-deep near-infrared spectrum of a compact quiescent galaxy at z=2.2
• UltraVISTA: a new ultra-deep near-infrared survey in COSMOS
• Molecfit: A general tool for telluric absorption correction. I. Method and application to ESO instruments
• A population of red candidate massive galaxies ~600 Myr after the Big Bang
• Molecfit: A general tool for telluric absorption correction II. Quantitative evaluation on ESO-VLT X-Shooter spectra
• COSMOS2020: A panchromatic view of the Universe to $z\sim 10$ from two complementary catalogs
• An ALMA survey of Sub-millimeter Galaxies in the Extended Chandra Deep Field South: Physical properties derived from ultraviolet-to-radio modelling
• The MOSFIRE Deep Evolution Field (MOSDEF) Survey: Rest-Frame Optical Spectroscopy for ~1500 H-Selected Galaxies at 1.37 < z < 3.8
• Two Remarkably Luminous Galaxy Candidates at $z\approx 10-12$ Revealed by JWST
• The Cosmic Evolution Survey (COSMOS): Subaru Observations of the HST COSMOS Field
• The Relation Between SFR and Stellar Mass for Galaxies at 3.5 $\le z\le$ 6.5 in CANDELS
• The stellar masses of 25000 galaxies at 0.2<z<1.0 estimated by the COMBO-17 survey
• The FLAMINGO project: cosmological hydrodynamical simulations for large-scale structure and galaxy cluster surveys
• 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
• A massive quiescent galaxy at redshift 4.658
• Confirmation and refutation of very luminous galaxies in the early universe
• The First Hyper-Luminous Infrared Galaxy Discovered by WISE
• COSMOS2020: The Galaxy Stellar Mass Function: the assembly and star formation cessation of galaxies at $0.2<z\le 7.5$
• Spectroscopic Confirmation of CEERS NIRCam-selected Galaxies at $\mathbf{z}\simeq 8-10$
• 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
• Submillimeter Follow-up of WISE-Selected Hyperluminous Galaxies
• A massive galaxy that formed its stars at $z\sim 11$
• The evolution of the galaxy stellar mass function over the last twelve billion years from a combination of ground-based and HST surveys
• 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
• An Extremely Massive Quiescent Galaxy at $z=3.493$: Evidence of Insufficiently Rapid Quenching Mechanisms in Theoretical Models
• Spectroscopic Confirmation of a Protocluster at $z=3.37$ with a High Fraction of Quiescent Galaxies
• A systematic search for very massive galaxies at z > 4
• 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
• Quantifying the Effects of Known Unknowns on Inferred High-redshift Galaxy Properties: Burstiness, the IMF, and Nebular Physics
• Tracing the Quenching Journey across Cosmic Time
• 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 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
• The kinematics of massive quiescent galaxies at $1.4<z<2.1$: dark matter fractions, IMF variation, and the relation to local early-type galaxies
• A Spitzer survey of Deep Drilling Fields to be targeted by the Vera C. Rubin Observatory Legacy Survey of Space and Time
• MAGAZ3NE: High Stellar Velocity Dispersions for Ultra-Massive Quiescent Galaxies at $z\gtrsim 3$
• Fast Outflows in Hot Dust-Obscured Galaxies with Keck/NIRES
• The Number Densities and Stellar Populations of Massive Galaxies at 3 < z < 6: A Diverse, Rapidly Forming Population in the Early Universe
• Implications of the Environments of Radio-detected AGN in a Complex Protostructure at z$\sim$3.3
• Broad emission lines in optical spectra of hot dust-obscured galaxies can contribute significantly to JWST/NIRCam photometry
• Missing Giants: Predictions on Dust-Obscured Galaxy Stellar Mass Assembly Throughout Cosmic Time
• A photo-z cautionary tale: Redshift confirmation of COSBO-7 at z=2.625
• Exploring the High-Mass End of the Stellar Mass Function of Star Forming Galaxies at Cosmic Noon
• NOEMA reveals the true nature of luminous red JWST z>10 galaxy candidates
• NOEMA Redshift Measurements of Extremely Bright Submillimeter Galaxies Near the GOODS-N

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