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Title: EVOLUTION OF GALAXY STELLAR MASS FUNCTIONS, MASS DENSITIES, AND MASS-TO-LIGHT RATIOS FROM z {approx} 7 TO z {approx} 4

Abstract

We derive stellar masses from spectral energy distribution fitting to rest-frame optical and UV fluxes for 401 star-forming galaxies at z {approx} 4, 5, and 6 from Hubble-WFC3/IR camera observations of the Early Release Science field combined with the deep GOODS-S Spitzer/IRAC data (and include a previously published z {approx} 7 sample). A mass-luminosity relation with strongly luminosity-dependent M/L{sub UV} ratios is found for the largest sample (299 galaxies) at z {approx} 4. The relation M{proportional_to}L{sub UV,1500}{sup 1.7({+-}0.2)} has a well-determined intrinsic sample variance of 0.5 dex. This relation is also consistent with the more limited samples at z {approx} 5-7. This z {approx} 4 mass-luminosity relation, and the well-established faint UV-luminosity functions at z {approx} 4-7, are used to derive galaxy mass functions (MFs) to masses M{approx}10{sup 8} at z {approx} 4-7. A bootstrap approach is used to derive the MFs to account for the large scatter in the M-{sub UV} relation and the luminosity function uncertainties, along with an analytical cross-check. The MFs are also corrected for the effects of incompleteness. The incompleteness-corrected MFs are steeper than previously found, with slopes {alpha}{sub M} {approx} -1.4 to -1.6 at low masses. These slopes are, however, still substantially flatter thanmore » the MFs obtained from recent hydrodynamical simulations. We use these MFs to estimate the stellar mass density (SMD) of the universe to a fixed M{sub UV,AB} < - 18 as a function of redshift and find an SMD growth {proportional_to}(1 + z){sup -3.4{+-}0.8} from z {approx} 7 to z {approx} 4. We also derive the SMD from the completeness-corrected MFs to a mass limit M{approx}10{sup 8} M{sub sun}. Such completeness-corrected MFs and the derived SMDs will be particularly important for comparisons as future MFs reach to lower masses.« less

Authors:
; ;  [1];  [2];  [3];  [4]
  1. Astronomy Department, University of California, Santa Cruz, CA 95064 (United States)
  2. Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)
  3. Leiden Observatory, Leiden University, NL-2300 RA Leiden (Netherlands)
  4. Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)
Publication Date:
OSTI Identifier:
21562553
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 735; Journal Issue: 2; Other Information: DOI: 10.1088/2041-8205/735/2/L34; Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DENSITY; ENERGY SPECTRA; FUNCTIONS; GALACTIC EVOLUTION; GALAXIES; LUMINOSITY; MASS; RED SHIFT; EVOLUTION; OPTICAL PROPERTIES; PHYSICAL PROPERTIES; SPECTRA

Citation Formats

Gonzalez, Valentino, Bouwens, Rychard J., Illingworth, Garth, Labbe, Ivo, Franx, Marijn, and Kriek, Mariska. EVOLUTION OF GALAXY STELLAR MASS FUNCTIONS, MASS DENSITIES, AND MASS-TO-LIGHT RATIOS FROM z {approx} 7 TO z {approx} 4. United States: N. p., 2011. Web. doi:10.1088/2041-8205/735/2/L34.
Gonzalez, Valentino, Bouwens, Rychard J., Illingworth, Garth, Labbe, Ivo, Franx, Marijn, & Kriek, Mariska. EVOLUTION OF GALAXY STELLAR MASS FUNCTIONS, MASS DENSITIES, AND MASS-TO-LIGHT RATIOS FROM z {approx} 7 TO z {approx} 4. United States. doi:10.1088/2041-8205/735/2/L34.
Gonzalez, Valentino, Bouwens, Rychard J., Illingworth, Garth, Labbe, Ivo, Franx, Marijn, and Kriek, Mariska. Sun . "EVOLUTION OF GALAXY STELLAR MASS FUNCTIONS, MASS DENSITIES, AND MASS-TO-LIGHT RATIOS FROM z {approx} 7 TO z {approx} 4". United States. doi:10.1088/2041-8205/735/2/L34.
@article{osti_21562553,
title = {EVOLUTION OF GALAXY STELLAR MASS FUNCTIONS, MASS DENSITIES, AND MASS-TO-LIGHT RATIOS FROM z {approx} 7 TO z {approx} 4},
author = {Gonzalez, Valentino and Bouwens, Rychard J. and Illingworth, Garth and Labbe, Ivo and Franx, Marijn and Kriek, Mariska},
abstractNote = {We derive stellar masses from spectral energy distribution fitting to rest-frame optical and UV fluxes for 401 star-forming galaxies at z {approx} 4, 5, and 6 from Hubble-WFC3/IR camera observations of the Early Release Science field combined with the deep GOODS-S Spitzer/IRAC data (and include a previously published z {approx} 7 sample). A mass-luminosity relation with strongly luminosity-dependent M/L{sub UV} ratios is found for the largest sample (299 galaxies) at z {approx} 4. The relation M{proportional_to}L{sub UV,1500}{sup 1.7({+-}0.2)} has a well-determined intrinsic sample variance of 0.5 dex. This relation is also consistent with the more limited samples at z {approx} 5-7. This z {approx} 4 mass-luminosity relation, and the well-established faint UV-luminosity functions at z {approx} 4-7, are used to derive galaxy mass functions (MFs) to masses M{approx}10{sup 8} at z {approx} 4-7. A bootstrap approach is used to derive the MFs to account for the large scatter in the M-{sub UV} relation and the luminosity function uncertainties, along with an analytical cross-check. The MFs are also corrected for the effects of incompleteness. The incompleteness-corrected MFs are steeper than previously found, with slopes {alpha}{sub M} {approx} -1.4 to -1.6 at low masses. These slopes are, however, still substantially flatter than the MFs obtained from recent hydrodynamical simulations. We use these MFs to estimate the stellar mass density (SMD) of the universe to a fixed M{sub UV,AB} < - 18 as a function of redshift and find an SMD growth {proportional_to}(1 + z){sup -3.4{+-}0.8} from z {approx} 7 to z {approx} 4. We also derive the SMD from the completeness-corrected MFs to a mass limit M{approx}10{sup 8} M{sub sun}. Such completeness-corrected MFs and the derived SMDs will be particularly important for comparisons as future MFs reach to lower masses.},
doi = {10.1088/2041-8205/735/2/L34},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 2,
volume = 735,
place = {United States},
year = {2011},
month = {7}
}