Tracing the Mass Growth and Star Formation Rate Evolution of Massive Galaxies from z~6 to z~1 in the Hubble Ultra-Deep Field

Abstract

We present an analysis of $\sim$1500 H160-selected photometric galaxies detected to a limiting magnitude of 27.8 in the HUDF, using imaging from the HST WFC3/IR camera in combination with archival UV, optical, and NIR imaging. We fit photometric redshifts and stellar population estimates for all galaxies with well-determined Spitzer IRAC fluxes, allowing for the determination of the cumulative mass function within the range $1<z<6$. By selecting samples of galaxies at a constant cumulative number density, we explore the co-evolution of stellar masses and star formation rates from z$\sim$6. We find a steady increase in the SFRs of galaxies at constant number density from z$\sim$6 to z$\sim$3. The peak epoch of star formation is found to shift to later times for galaxies with increasing number densities, in agreement with the expectations from cosmic downsizing. The observed SFRs can fully account for the mass growth to z$\sim$2 amongst galaxies with cumulative number densities greater than 10${}^{-3.5}$ Mpc${}^{-3}$. For galaxies with a lower constant number density we find the observed stellar masses are $\sim$3 times greater than that which may be accounted for by the observed star formation alone at late times, implying that growth from mergers plays an important role at $z<2$. We additionally observe a decreasing sSFR, equivalent to approximately one order of magnitude, from z$\sim$6 to z$\sim$2 amongst galaxies with number densities less than 10${}^{-3.5}$ Mpc${}^{-3}$ along with significant evidence that at any redshift the sSFR is higher for galaxies at higher number density. The combination of these findings can qualitatively explain the previous findings of a sSFR plateau at high redshift. Tracing the evolution of the fraction of quiescent galaxies for samples matched in cumulative number density over this redshift range, we find no unambiguous examples of quiescent galaxies at $z>4$.

21 pages, 16 figures; Accepted for publication in ApJ

References in corpus (17)

• EAZY: A Fast, Public Photometric Redshift Code
• 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
• The Hubble Ultra Deep Field
• UV Luminosity Functions at z~4, 5, and 6 from the HUDF and other Deep HST ACS Fields: Evolution and Star Formation History
• Mass, Metal, and Energy Feedback in Cosmological Simulations
• Star formation in AEGIS field galaxies since z=1.1 . Staged galaxy formation, and a model of mass-dependent gas exhaustion
• What do we learn from IRAC observations of galaxies at 2 < z < 3.5?
• The dependence of Star Formation on Galaxy Stellar Mass
• Deep U band and R imaging of GOODS-South: Observations,data reduction and first results
• The evolution of the specific star formation rate of massive galaxies to z ~ 1.8 in the E-CDFS
• Constructing Merger Trees that Mimic N-Body Simulations
• The UDF05 Follow-up of the HUDF: I. The Faint-End Slope of the Lyman-Break Galaxy Population at z~5
• Constraints on Physical Properties of z~6 Galaxies Using Cosmological Hydrodynamic Simulations
• The Color Magnitude Distribution of Field Galaxies to z~3: the evolution and modeling of the blue sequence
• Emission-Line Galaxies from the PEARS Hubble Ultra Deep Field: A 2-D Detection Method and First Results
• Where can we really find the First Stars' Remnants today?

Cited by in corpus (21)

• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• 3D-HST WFC3-selected Photometric Catalogs in the Five CANDELS/3D-HST Fields: Photometry, Photometric Redshifts and Stellar Masses
• The Evolution of the Galaxy Rest-Frame Ultraviolet Luminosity Function Over the First Two Billion Years
• Modelling and interpreting spectral energy distributions of galaxies with BEAGLE
• The Relation Between SFR and Stellar Mass for Galaxies at 3.5 $\le z\le$ 6.5 in CANDELS
• Noise Based Detection and Segmentation of Nebulous Objects
• ZFOURGE/CANDELS: On the Evolution of M* Galaxy Progenitors from z=3 to 0.5
• The Argo Simulation: I. Quenching of Massive Galaxies at High Redshift as a Result of Cosmological Starvation
• Observations of environmental quenching in groups in the 11 Gyr since z=2.5: different quenching for central and satellite galaxies
• On the importance of using appropriate spectral models to derive physical properties of galaxies at 0.7<z<2.8
• Spatially-unresolved SED fitting can underestimate galaxy masses: a solution to the missing mass problem
• Minor vs Major Mergers: The Stellar Mass Growth of Massive Galaxies from z=3 using Number Density Selection Techniques
• Weak Lensing Reveals a Tight Connection Between Dark Matter Halo Mass and the Distribution of Stellar Mass in Massive Galaxies
• 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
• Effects of the initial conditions on cosmological $N$-body simulations
• A large difference in the progenitor masses of active and passive galaxies in the EAGLE simulation
• The Differing Relationships Between Size, Mass, Metallicity and Core Velocity Dispersion of Central and Satellite Galaxies
• The X-shooter Lens Survey - II. Sample presentation and spatially resolved kinematics
• Galaxy growth from redshift 5 to 0 at fixed comoving number density
• Accurate PSF-matched photometry and photometric redshifts for the Extreme Deep Field with the Chebyshev-Fourier functions
• The average structural evolution of massive galaxies can be reliably estimated using cumulative galaxy number densities