UV-DROPOUT GALAXIES IN THE GOODS-SOUTH FIELD FROM WFC3 EARLY RELEASE SCIENCE OBSERVATIONS

Journal Article · Fri Sep 10 04:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/720/2/1708· OSTI ID:21460019

Hathi, N P ^[1]; Ryan, R E ^[2]; Cohen, S H; Windhorst, R A; Rutkowski, M J ^[3]; Yan, H ^[4]; McCarthy, P J ^[5]; O'Connell, R W ^[6]; Koekemoer, A M; Bond, H E ^[7]; Balick, B ^[8]; Calzetti, D ^[9]; Disney, M J ^[10]; Dopita, M A ^[11]; Frogel, Jay A ^[12]; Hall, D N. B. ^[13]; Holtzman, J A ^[14]; Kimble, R A ^[15]; Paresce, F ^[16]; Saha, A ^[17]

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1. Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States)
2. Department of Physics and Astronomy, University of California, Davis, CA 92616 (United States)
3. School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States)
4. Center for Cosmology and AstroParticle Physics, Ohio State University, Columbus, OH 43210 (United States)
5. Observatories of the Carnegie Institute of Washington, Pasadena, CA 91101 (United States)
6. Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States)
7. Space Telescope Science Institute, Baltimore, MD 21218 (United States)
8. Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States)
9. Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)
10. School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom)
11. Research School of Astronomy and Astrophysics, The Australian National University, ACT 2611 (Australia)
12. Association of Universities for Research in Astronomy, Washington, DC 20005 (United States)
13. Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States)
14. Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States)
15. NASA-Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
16. Istituto di Astrofisica Spaziale e Fisica Cosmica, INAF, Via Gobetti 101, 40129 Bologna (Italy)
17. National Optical Astronomy Observatories, Tucson, AZ 85726-6732 (United States)

We combine new high sensitivity ultraviolet (UV) imaging from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) with existing deep HST/Advanced Camera for Surveys optical images from the Great Observatories Origins Deep Survey (GOODS) program to identify UV-dropouts, which are Lyman break galaxy (LBG) candidates at z {approx_equal} 1-3. These new HST/WFC3 observations were taken over 50 arcmin{sup 2} in the GOODS-South field as a part of the Early Release Science program. The uniqueness of these new UV data is that they are observed in three UV/optical (WFC3 UVIS) channel filters (F225W, F275W, and F336W), which allows us to identify three different sets of UV-dropout samples. We apply Lyman break dropout selection criteria to identify F225W-, F275W-, and F336W-dropouts, which are z {approx_equal} 1.7, 2.1, and 2.7 LBG candidates, respectively. We use multi-wavelength imaging combined with available spectroscopic and photometric redshifts to carefully access the validity of our UV-dropout candidates. Our results are as follows: (1) these WFC3 UVIS filters are very reliable in selecting LBGs with z {approx_equal} 2.0, which helps to reduce the gap between the well-studied z {approx}> 3 and z {approx} 0 regimes; (2) the combined number counts with average redshift z {approx_equal} 2.2 agree very well with the observed change in the surface densities as a function of redshift when compared with the higher redshift LBG samples; and (3) the best-fit Schechter function parameters from the rest-frame UV luminosity functions at three different redshifts fit very well with the evolutionary trend of the characteristic absolute magnitude, M*, and the faint-end slope, {alpha}, as a function of redshift. This is the first study to illustrate the usefulness of the WFC3 UVIS channel observations to select z {approx}< 3 LBGs. The addition of the new WFC3 on the HST has made it possible to uniformly select LBGs from z {approx_equal} 1 to z {approx_equal} 9 and significantly enhance our understanding of these galaxies using HST sensitivity and resolution.

• OSTI ID: 21460019
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 720; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ELECTROMAGNETIC RADIATION
EVOLUTION
GALACTIC EVOLUTION
GALAXIES
LUMINOSITY
MASS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATIONS
RED SHIFT
TELESCOPES
ULTRAVIOLET RADIATION
WAVELENGTHS