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Title: THE BRIGHT END OF THE ULTRAVIOLET LUMINOSITY FUNCTION AT z {approx} 8: NEW CONSTRAINTS FROM CANDELS DATA IN GOODS-SOUTH

Abstract

We present new z {approx} 8 galaxy candidates from a search over {approx}95 arcmin{sup 2} of WFC3/IR data, tripling the previous search area for bright z {approx} 8 galaxies. Our analysis uses newly acquired WFC3/IR imaging data from the CANDELS Multi-Cycle Treasury program over the GOODS-South field. These new data are combined with existing deep optical Advanced Camera for Surveys (ACS) imaging to search for relatively bright (M {sub UV} < -19.5 mag) z {approx} 8 galaxy candidates using the Lyman break technique. These new candidates are used to determine the bright end of the UV luminosity function (LF) of star-forming galaxies at z {approx} 7.2-8.7, i.e., a cosmic age of 600 {+-} 80 Myr. To minimize contamination from lower redshift galaxies, we make full use of all optical ACS data and impose strict non-detection criteria based on an optical {chi}{sup 2} {sub opt} flux measurement. In the whole search area, we identify 16 candidate z {approx} 8 galaxies, spanning a magnitude range H {sub 160,AB} = 25.7-27.9 mag. The new data show that the UV LF is a factor {approx}1.7 lower at M {sub UV} < -19.5 mag than determined from the HUDF09 and Early Release Science (ERS) datamore » alone. Combining this new sample with the previous candidates from the HUDF09 and ERS data allows us to perform the most accurate measurement of the z {approx} 8 UV LF yet. Schechter function fits to the combined data result in a best-fit characteristic magnitude of M {sub *}(z = 8) = -20.04 {+-} 0.46 mag. The faint-end slope is very steep, though quite uncertain, with {alpha} = -2.06 {+-} 0.32. A combination of wide-area data with additional ultra-deep imaging will be required to significantly reduce the uncertainties on these parameters in the future.« less

Authors:
; ; ;  [1]; ; ;  [2];  [3];  [4];  [5]
  1. UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States)
  2. Leiden Observatory, Leiden University, NL-2300 RA Leiden (Netherlands)
  3. Center for Astrophysics and Space Astronomy, University of Colorado, 389-UCB, Boulder, CO 80309 (United States)
  4. Department of Astronomy, Yale University, New Haven, CT 06520 (United States)
  5. Institute for Astronomy, ETH Zurich, 8092 Zurich (Switzerland)
Publication Date:
OSTI Identifier:
22086370
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 759; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTRONOMY; ASTROPHYSICS; CAMERAS; GALACTIC EVOLUTION; GALAXIES; LUMINOSITY; MASS; RED SHIFT; STARS; ULTRAVIOLET RADIATION

Citation Formats

Oesch, P. A., Illingworth, G. D., Gonzalez, V., Magee, D., Bouwens, R. J., Franx, M., Labbe, I., Trenti, M., Van Dokkum, P. G., and Carollo, C. M., E-mail: poesch@ucolick.org. THE BRIGHT END OF THE ULTRAVIOLET LUMINOSITY FUNCTION AT z {approx} 8: NEW CONSTRAINTS FROM CANDELS DATA IN GOODS-SOUTH. United States: N. p., 2012. Web. doi:10.1088/0004-637X/759/2/135.
Oesch, P. A., Illingworth, G. D., Gonzalez, V., Magee, D., Bouwens, R. J., Franx, M., Labbe, I., Trenti, M., Van Dokkum, P. G., & Carollo, C. M., E-mail: poesch@ucolick.org. THE BRIGHT END OF THE ULTRAVIOLET LUMINOSITY FUNCTION AT z {approx} 8: NEW CONSTRAINTS FROM CANDELS DATA IN GOODS-SOUTH. United States. doi:10.1088/0004-637X/759/2/135.
Oesch, P. A., Illingworth, G. D., Gonzalez, V., Magee, D., Bouwens, R. J., Franx, M., Labbe, I., Trenti, M., Van Dokkum, P. G., and Carollo, C. M., E-mail: poesch@ucolick.org. Sat . "THE BRIGHT END OF THE ULTRAVIOLET LUMINOSITY FUNCTION AT z {approx} 8: NEW CONSTRAINTS FROM CANDELS DATA IN GOODS-SOUTH". United States. doi:10.1088/0004-637X/759/2/135.
@article{osti_22086370,
title = {THE BRIGHT END OF THE ULTRAVIOLET LUMINOSITY FUNCTION AT z {approx} 8: NEW CONSTRAINTS FROM CANDELS DATA IN GOODS-SOUTH},
author = {Oesch, P. A. and Illingworth, G. D. and Gonzalez, V. and Magee, D. and Bouwens, R. J. and Franx, M. and Labbe, I. and Trenti, M. and Van Dokkum, P. G. and Carollo, C. M., E-mail: poesch@ucolick.org},
abstractNote = {We present new z {approx} 8 galaxy candidates from a search over {approx}95 arcmin{sup 2} of WFC3/IR data, tripling the previous search area for bright z {approx} 8 galaxies. Our analysis uses newly acquired WFC3/IR imaging data from the CANDELS Multi-Cycle Treasury program over the GOODS-South field. These new data are combined with existing deep optical Advanced Camera for Surveys (ACS) imaging to search for relatively bright (M {sub UV} < -19.5 mag) z {approx} 8 galaxy candidates using the Lyman break technique. These new candidates are used to determine the bright end of the UV luminosity function (LF) of star-forming galaxies at z {approx} 7.2-8.7, i.e., a cosmic age of 600 {+-} 80 Myr. To minimize contamination from lower redshift galaxies, we make full use of all optical ACS data and impose strict non-detection criteria based on an optical {chi}{sup 2} {sub opt} flux measurement. In the whole search area, we identify 16 candidate z {approx} 8 galaxies, spanning a magnitude range H {sub 160,AB} = 25.7-27.9 mag. The new data show that the UV LF is a factor {approx}1.7 lower at M {sub UV} < -19.5 mag than determined from the HUDF09 and Early Release Science (ERS) data alone. Combining this new sample with the previous candidates from the HUDF09 and ERS data allows us to perform the most accurate measurement of the z {approx} 8 UV LF yet. Schechter function fits to the combined data result in a best-fit characteristic magnitude of M {sub *}(z = 8) = -20.04 {+-} 0.46 mag. The faint-end slope is very steep, though quite uncertain, with {alpha} = -2.06 {+-} 0.32. A combination of wide-area data with additional ultra-deep imaging will be required to significantly reduce the uncertainties on these parameters in the future.},
doi = {10.1088/0004-637X/759/2/135},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 759,
place = {United States},
year = {2012},
month = {11}
}