CLASH: DISCOVERY OF A BRIGHT z {approx_equal} 6.2 DWARF GALAXY QUADRUPLY LENSED BY MACS J0329.6-0211

Journal Article · Thu Mar 15 00:00:00 EDT 2012 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/747/1/L9· OSTI ID:22048019

Zitrin, A ^[1]; Moustakas, J ^[2]; Bradley, L; Coe, D; Postman, M; Koekemoer, A ^[3]; Moustakas, L A ^[4]; Shu, X ^[5]; Zheng, W; Ford, H ^[6]; Benitez, N ^[7]; Bouwens, R ^[8]; Broadhurst, T ^[9]; Host, O; Jouvel, S ^[10]; Meneghetti, M ^[11]; Rosati, P ^[12]; Donahue, M ^[13]; Grillo, C ^[14]; Kelson, D ^[15] ; others, and

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1. Institut fuer Theoretische Astrophysik, Universitaet Heidelberg, Heidelberg (Germany)
2. Center for Astrophysics and Space Sciences, University of California, San Diego, CA (United States)
3. Space Telescope Science Institute, Baltimore, MD (United States)
4. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA (United States)
5. Department of Astronomy, University of Science and Technology of China, Hefei, Anhui (China)
6. Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD (United States)
7. Instituto de Astrofisica de Andalucia (CSIC), Granada (Spain)
8. Leiden Observatory, University of Leiden, Leiden (Netherlands)
9. Department of Theoretical Physics, University of Basque Country, Bilbao (Spain)
10. Department of Physics and Astronomy, University College London, London (United Kingdom)
11. INAF, Osservatorio Astronomico di Bologna, Bologna (Italy)
12. European Southern Observatory, Garching bei Muenchen (Germany)
13. Physics and Astronomy Department, Michigan State University, East Lansing, MI (United States)
14. Excellence Cluster Universe, Technische Universitaet Muenchen, Muenchen (Germany)
15. Observatories of the Carnegie Institution of Washington, Pasadena, CA (United States)

We report the discovery of a z{sub phot} = 6.18{sup +0.05}{sub -0.07} (95% confidence level) dwarf galaxy, lensed into four images by the galaxy cluster MACS J0329.6-0211 (z{sub l} = 0.45). The galaxy is observed as a high-redshift dropout in HST/ACS/WFC3 CLASH and Spitzer/IRAC imaging. Its redshift is securely determined due to a clear detection of the Lyman break in the 18-band photometry, making this galaxy one of the highest-redshift multiply lensed objects known to date with an observed magnitude of F125W =24.00 {+-} 0.04 AB mag for its most magnified image. We also present the first strong-lensing analysis of this cluster uncovering 15 additional multiply imaged candidates of five lower-redshift sources spanning the range z{sub s} {approx_equal} 2-4. The mass model independently supports the high photometric redshift and reveals magnifications of 11.6{sup +8.9}{sub -4.1}, 17.6{sup +6.2}{sub -3.9}, 3.9{sup +3.0}{sub -1.7}, and 3.7{sup +1.3}{sub -0.2}, respectively, for the four images of the high-redshift galaxy. By delensing the most magnified image we construct an image of the source with a physical resolution of {approx}200 pc when the universe was {approx}0.9 Gyr old, where the z {approx_equal} 6.2 galaxy occupies a source-plane area of approximately 2.2 kpc{sup 2}. Modeling the observed spectral energy distribution using population synthesis models, we find a demagnified stellar mass of {approx}10{sup 9} M{sub Sun }, subsolar metallicity (Z/Z{sub Sun} {approx} 0.5), low dust content (A{sub V} {approx} 0.1 mag), a demagnified star formation rate (SFR) of {approx}3.2 M{sub Sun} yr{sup -1}, and a specific SFR of {approx}3.4 Gyr{sup -1}, all consistent with the properties of local dwarf galaxies.

• OSTI ID: 22048019
• Journal Information: Astrophysical Journal Letters, Vol. 747, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTROPHYSICS
COSMIC DUST
ENERGY SPECTRA
GALAXIES
GALAXY CLUSTERS
GRAVITATIONAL LENSES
LYMAN LINES
MASS
NONLUMINOUS MATTER
PHOTOMETRY
RED SHIFT
RESOLUTION
STAR EVOLUTION
STARS
UNIVERSE