Galaxies at z ~ 6: The UV Luminosity Function and Luminosity Density from 506 HUDF, HUDF Parallel ACS Field, and GOODS i-Dropouts

By R. Bouwens, G. Illingworth, M. Franx, J. Blakeslee. 2005

267 citations recorded by the source corpus.

We have detected 506 i-dropouts (z ~ 6 galaxies) in deep, wide-area HST ACS fields: HUDF, enhanced GOODS, and HUDF parallel ACS fields (HUDF-Ps). The contamination levels are ≲8% (i.e., ≳92% are at z ~ 6). With these samples, we present the most comprehensive, quantitative analyses of z ~ 6 galaxies yet and provide optimal measures of the UV luminosity function (LF) and luminosity density at z ~ 6, and their evolution to z ~ 3. We redetermine the size and color evolution from z ~ 6 to z ~ 3. Field-to-field variations (cosmic variance), completeness, flux, and contamination corrections are modeled systematically and quantitatively. After corrections, we derive a rest-frame continuum UV (~1350 Å) LF at z ~ 6 that extends to M1350,AB ~ -17.5 (0.04L). There is strong evidence for evolution of the LF between z ~ 6 and z ~ 3, most likely through a brightening (0.6 ± 0.2 mag) of M* (at 99.7% confidence), although the degree depends on the faint-end slope. As expected from hierarchical models, the most luminous galaxies are deficient at z ~ 6. Density evolution (ϕ*) is ruled out at >99.99% confidence. Despite large changes in the LF, the luminosity density at z ~ 6 is similar to (0.82 ± 0.21 times) that at z ~ 3. Changes in the mean UV color of galaxies from z ~ 6 to z ~ 3 suggest an evolution in dust content, indicating that the true evolution is substantially larger: at z ~ 6 the star formation rate density is just ~30% of the z ~ 3 value. Our UV LF is consistent with z ~ 6 galaxies providing the necessary UV flux to reionize the universe.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/118749f476d4fff17f624e5cd6bf3d4e6272d395

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Instrumentation

Citations in the corpus

A SURVEY OF z ∼ 6 QUASARS IN THE SLOAN DIGITAL SKY SURVEY DEEP STRIPE. I. A FLUX-LIMITED SAMPLE AT zAB < 21 (2007, background): “Galaxies probably can provide enough photons for the reionization (e.g. Yan & Windhorst 2004; Bouwens et al. 2006; Kashikawa et al. 2006; McQuinn et al. 2007), however, the individual contributions of galaxies and quasars to the reionization are not well determined.”
SPECTROSCOPIC OBSERVATIONS OF LYMAN BREAK GALAXIES AT REDSHIFTS ∼4, 5, AND 6 IN THE GOODS-SOUTH FIELD (2009, background): “…from both ground– and space–based observatories (Shimasaku et al. 2005; Iwata et al. 2003; Giavalisco et al. 2004b; Dickinson et al. 2004; Bunker et al. 2004; Bouwens et al. 2006, 2007); these samples, however, are exclusively photometric ones, with small numbers of spectroscopic identifications.”
REIONIZATION AFTER PLANCK: THE DERIVED GROWTH OF THE COSMIC IONIZING EMISSIVITY NOW MATCHES THE GROWTH OF THE GALAXY UV LUMINOSITY DENSITY (2015, background): “…redshift dependence of the result is due to the inclusion of much lowerluminosity galaxies in the calculated luminosity densities and the strong evidence that the UV luminosity density evolves faster at the bright end than the faint end (e.g., Bouwens et al. 2006, 2008; Yoshida et al. 2006; B15).”
The contribution of high-redshift galaxies to cosmic reionization: New results from deep WFC3 imaging of the Hubble Ultra Deep Field (2009, methodology): “We also find evidence that the z ∼ 6 luminosity function of Bouwens et al. (2006) over-predicts the number of z′-drops at z = 7 by a factor of 2−3, suggesting evolution in the star forming population from z = 7 − 6.”
Dust in the Reionization Era: ALMA Observations of a z = 8.38 Gravitationally Lensed Galaxy (2017, methodology): “To derive the total flux, we applied an aperture correction based on the F160W MAG AUTO measure (see e.g. Bouwens et al. 2006).”
Dusty Star Forming Galaxies at High Redshift (2014, background): “This is determined by observed rest-frame ultraviolet luminosity functions (e.g. Bouwens et al., 2006; Reddy et al., 2008; Oesch et al., 2010) at high redshift and the observed main sequence (Noeske et al., 2007b; Stark et al., 2013).”
The VISTA deep extragalactic observations (VIDEO) survey (2012, background): “…VIDEO, to show that the bright end of the galaxy luminosity function at z ∼ 6 follows an exponential decline and that these massive galaxies appear to be both larger and more dusty than their fainter counterparts discovered in deep Hubble Space Telescope (HST) imaging (e.g. Bouwens et al. 2006).”
The observed ionization rate of the intergalactic medium and the ionizing emissivity at z≥ 5: evidence for a photon-starved and extended epoch of reionization (2007, methodology): “We attempt to take into account the uncertainty in the emissivity by integrating equation (7) to two different lower luminosity limits, roughly corresponding to the faint end limits of the surveys by Yoshida et al. (2006) and Bouwens et al. (2006).”
z ~ 7-10 Galaxies in the HUDF and GOODS Fields: UV Luminosity Functions (2008, methodology): “Some groups (Shimasaku et al. 2005; Bouwens et al. 2006; Yoshida et al. 2006; Ouchi et al. 2004a; Bouwens et al. 2007; Dickinson et al. 2004) have argued the evolution occurs primarily at bright end of the LF, others (Iwata et al. 2003; Sawicki & Thompson 2006; Iwata et al. 2007) have asserted it…”
The rising star formation histories of distant galaxies and implications for gas accretion with time (2010, background): “Many studies have measured UV luminosity functions of galaxies from z ∼ 2 to z & 8 (e.g., Bouwens et al. 2004, 2006, 2010b,a; Reddy & Steidel 2009; Oesch et al. 2010b; McLure et al. 2010).”
Measurements of the UV background at 4.6 < z < 6.4 using the quasar proximity effect (2010, background): “Direct searches for these sources atz & 6 − 10 have taken advantage of recent very deep optical and near-infrared imaging from both the ground and space (Bunker et al. 2004; Bouwens et al. 2006; Yoshida etal.”
The VIMOS VLT Deep Survey - Evolution of the major merger rate since z ~ 1 from spectroscopically confirmed galaxy pairs (2008, unknown): “…to quantify the contribution of merging to the evolution process and its impact on important quantities like the cosmic star formation rate (e.g. Bouwens et al., 2006; Tresse et al., 2007; Woods et al., 2006) or the global stellar mass density (e.g. Arnouts et al., 2007; Bundy et al., 2005;…”
A critical analysis of the ultraviolet continuum slopes (β) of high-redshift galaxies: no evidence (yet) for extreme stellar populations at z > 6 (2011, background): “…aroundλrest ≃ 1500Å than have been detected to date in galaxies discovered at any lower redshiftz < 6.5 (e.g. Steidel et al. 1999; Meurer et al. 1999; Adelberger & Steidel2000; Ouchi et al. 2004; Stanway et al. 2005; Bouwens et al. 2006; Hathi et al. 2008; Bouwens et al. 2009; Erb et al. 2010).”
Lyα-EMITTING GALAXIES AT z = 2.1 IN ECDF-S: BUILDING BLOCKS OF TYPICAL PRESENT-DAY GALAXIES? (2009, methodology): “This has allowed an exploration of star-forming galaxies at redshifts 3 ≤ z ≤ 8 via imaging from ground and space (e.g. Steidel et al. 2003, Bouwens et al. 2006, Ouchi et al. 2008) and spectroscopy on 8–10 meter telescopes (e.g. Shapley et al. 2001, Shapley et al. 2003).”
THE CLUSTER LENSING AND SUPERNOVA SURVEY WITH HUBBLE: AN OVERVIEW (2011, background): “These efforts have proven successful at finding objects at z < 7, but there is growing evidence for a rapid decrease in the number of candidates at higher redshifts (Iye et al. 2006; Bouwens et al. 2006; Castellano et al. 2010).”
Fluctuations in the high-redshift Lyman–Werner background: close halo pairs as the origin of supermassive black holes (2008, methodology): “One can reproduce the observed rest–frame UV luminosity function of Lyman Break Galaxies at z ∼ 6 in the Hubble Deep Fields (Bouwens et al. 2006) by simply assuming that a fraction ǫDC ∼ 0.1 of all dark matter halos are converting f∗ ∼ 0.1 of their gas into stars over their duty–cycle of ǫDCthub ∼ 0”
A STEEP FAINT-END SLOPE OF THE UV LUMINOSITY FUNCTION AT z ∼ 2–3: IMPLICATIONS FOR THE GLOBAL STELLAR MASS DENSITY AND STAR FORMATION IN LOW-MASS HALOS (2008, methodology): “With this model, galaxies at the faint-end of the UV LF (M(1700Å) ≈ −18.00) will have close to zero reddening, similar to the mean reddening (as inferred from the rest-UV slopes) of dropout galaxies at z ∼ 6 with comparable unobscured UV luminosities (Bouwens et al. 2006).”
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 (2011, methodology): “While such an evolution in colors had already been found over the redshift range z ∼ 5-6 to z ∼ 3- 4 (Lehnert & Bremer 2003; Stanway et al. 2005; Bouwens et al. 2006, 2009, 2010a), this confirms this result at much higher confidence.”
THE EVOLUTIONARY HISTORY OF LYMAN BREAK GALAXIES BETWEEN REDSHIFT 4 AND 6: OBSERVING SUCCESSIVE GENERATIONS OF MASSIVE GALAXIES IN FORMATION (2009, background): “Standard contaminants include cool stars and dusty or old galaxies at lowerredshifts (e.g., Stanway et al. 2004; Beckwith et al. 2006; Bouwens et al. 2006).”