Color Distributions, Number and Mass Densities of Massive Galaxies at 1.5 < z < 3: Comparing Observations with Merger Simulations

Abstract

We present a comparison between the observed color distribution, number and mass density of massive galaxies at 1.5 < z < 3 and a model by Hopkins et al. that relates the quasar and galaxy population on the basis of gas-rich mergers. In order to test the hypothesis that quiescent red galaxies are formed after a gas-rich merger involving quasar activity, we confront photometry of massive (M > 4x10^10 Msun) galaxies extracted from the FIRES, GOODS-South, and MUSYC surveys, together spanning an area of 496 arcmin^2, with synthetic photometry from hydrodynamical merger simulations. As in the Hopkins et al. (2006b) model, we use the observed quasar luminosity function to estimate the merger rate. We find that the synthetic U-V and V-J colors of galaxies that had a quasar phase in their past match the colors of observed galaxies that are best characterized by a quiescent stellar population. At z ~ 2.6, the observed number and mass density of quiescent red galaxies with M > 4x10^10 Msun is consistent with the model in which every quiescent massive galaxy underwent a quasar phase in the past. At z ~ 1.9, 2.8 times less quiescent galaxies are observed than predicted by the model as descendants of higher redshift quasars. The merger model also predicts a large number of galaxies undergoing merger-driven star formation. We find that the predicted number and mass density accounts for 30-50% of the observed massive star-forming galaxies. However, their colors do not match those of observed star-forming galaxies. In particular, the colors of dusty red galaxies are not reproduced by the simulations. Several possible origins of this discrepancy are discussed. The observational constraints on the validity of the model are currently limited by cosmic variance and uncertainties in stellar population synthesis and radiative transfer.

Accepted for publication in the Astrophysical Journal, 24 pages, 14 figures (updated reference list)

References in corpus (29)

• EAZY: A Fast, Public Photometric Redshift Code
• Cold streams in early massive hot haloes as the main mode of galaxy formation
• The hierarchical formation of the brightest cluster galaxies
• A Semi-Analytic Model for the Co-evolution of Galaxies, Black Holes, and Active Galactic Nuclei
• An Observational Determination of the Bolometric Quasar Luminosity Function
• Detection of quiescent galaxies in a bicolor sequence from z=0-2
• From rings to bulges: evidence for rapid secular galaxy evolution at z~2 from integral field spectroscopy in the SINS survey
• The rapid formation a large rotating disk galaxy three billion years after the Big Bang
• Structure and star formation in galaxies out to z=3: evidence for surface density dependent evolution and upsizing
• Evidence for TP-AGB stars in high redshift galaxies, and their effect on deriving stellar population parameters
• Kinematic Structure of Merger Remnants
• What do we learn from IRAC observations of galaxies at 2 < z < 3.5?
• Multiwavelength study of massive galaxies at z~2. II. Widespread Compton thick AGN and the concurrent growth of black holes and bulges
• Formation of z ~ 6 quasars from hierarchical galaxy mergers
• Sunrise: Polychromatic Dust Radiative Transfer in Arbitrary Geometries
• How Mergers May Affect The Mass Scaling Relations Between Black Holes, Galaxies, and Other Gravitationally Bound Systems
• Kinemetry of SINS High-Redshift Star-Forming Galaxies: Distinguishing Rotating Disks from Major Mergers
• Modelling the Pan-Spectral Energy Distribution of Starburst Galaxies: IV The Controlling Parameters of the Starburst SED
• Dissipation and Extra Light in Galactic Nuclei: II. 'Cusp' Ellipticals
• A Theoretical Interpretation of the Black Hole Fundamental Plane
• Dissipation and Extra Light in Galactic Nuclei: I. Gas-Rich Merger Remnants
• The Detection of a Red Sequence of Massive Field Galaxies at z~2.3 and its Evolution to z~0
• The rest-frame optical luminosity functions of galaxies at 2<z<3.5
• Clustering of K-selected Galaxies at 2<z<3.5: Evidence for a Color-Density Relation
• Erratum - The many lives of AGN: cooling flows, black holes and the luminosities and colours of galaxies
• A Confirmation of the Strong Clustering of Distant Red Galaxies at 2 < z <3
• The merger-driven evolution of warm infrared luminous galaxies
• Dynamical properties of a large young disk galaxy at z=2.03
• Dust Attenuation in Hydrodynamic Simulations of Spiral Galaxies

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• Colour gradients in cluster ellipticals at z~1.4: the hidden content of the galaxy central regions
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