TWO LENSED z {approx_equal} 3 LYMAN BREAK GALAXIES DISCOVERED IN THE SDSS GIANT ARCS SURVEY

Journal Article · Mon Nov 01 04:00:00 EDT 2010 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/723/1/L73· OSTI ID:21452706

Koester, Benjamin P; Gladders, Michael D; Sharon, Keren; Wuyts, Eva; Bayliss, Matthew B ^[1]; Hennawi, Joseph F ^[2]; Rigby, J R ^[3]; Dahle, Hakon ^[4]

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1. Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States)
2. Max Planck Institut fur Astronomie, Konigstuhl 17, D-69117 Heidelberg (Germany)
3. Observatories, Carnegie Institution of Washington, 813 Santa Barbara St., Pasadena, CA 91101 (United States)
4. Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029, Blindern, N-0315 Oslo (Norway)

We report the discovery of two strongly lensed z {approx} 3 Lyman break galaxies (LBGs) discovered as u-band dropouts as part of the SDSS Giant Arcs Survey (SGAS). The first, SGAS J122651.3+215220 at z = 2.9233, is lensed by one of several sub-clusters, SDSS J1226+2152, in a complex massive cluster at z = 0.43. Its (g, r, i) magnitudes are (21.14, 20.60, 20.51) which translate to surface brightnesses, {mu} {sub g,r,i}, of (23.78, 23.11, 22.81). The second, SGAS J152745.1+065219, is an LBG at z = 2.7593 lensed by the foreground SDSS J1527+0652 at z = 0.39, with (g, r, z) = (20.90, 20.52, 20.58) and {mu} {sub g,r,z} = (25.15, 24.52, 24.12). Moderate resolution spectroscopy confirms the redshifts suggested by photometric breaks and shows both absorption and emission features typical of LBGs. Lens mass models derived from combined imaging and spectroscopy reveal that SGAS J122651.3+215220 is a highly magnified source (M {approx_equal} 40), while SGAS J152745.1+065219 is magnified by no more than M {approx_equal} 15. Compared with LBG survey results, the luminosities and lensing-corrected magnitudes suggest that SGAS J122651.3+215220 is among the faintest {approx_equal}20% of LBGs in that sample. SGAS J152745.1+065219, on the other hand, has an unlensed r-band apparent magnitude similar to that of the 'Cosmic Eye', which places it near the mean of LBG survey results over similar redshifts.

• OSTI ID: 21452706
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 723; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION
BRIGHTNESS
EVOLUTION
GALACTIC EVOLUTION
GALAXIES
LUMINOSITY
MASS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RED SHIFT
SORPTION
SPECTROSCOPY
UNIVERSE