DISCOVERY OF A VERY BRIGHT, STRONGLY LENSED z=2 GALAXY IN THE SDSS DR5

作者：Lin Huan^*; Buckley Geer Elizabeth; Allam Sahar S; Tucker Douglas L; Diehl H Thomas; Kubik Donna; Kubo Jeffrey M; Annis James; Frieman Joshua A; Oguri Masamune; Inada Naohisa

来源：Astrophysical Journal, 2009, 699(2): 1242-1251.

DOI：10.1088/0004-637X/699/2/1242

• galaxies: high-redshift
• gravitational lensing

We report on the discovery of a very bright z = 2.00 star-forming galaxy that is strongly lensed by a foreground z = 0.422 luminous red galaxy (LRG), SDSS J120602.09+514229.5. This system, nicknamed the "Clone," was found in a systematic search for bright arcs lensed by LRGs and brightest cluster galaxies in the Sloan Digital Sky Survey Data Release 5 sample. Follow-up observations on the Subaru 8.2 m telescope on Mauna Kea and the Astrophysical Research Consortium 3.5 m telescope at Apache Point Observatory confirmed the lensing nature of this system. A simple lens model for the system, assuming a singular isothermal ellipsoid mass distribution, yields an Einstein radius of theta(Ein) = 3.82 +/- 0.03 or 14.8 +/- 0.1 h(-1) kpc at the lens redshift. The total projected mass enclosed within the Einstein radius is 2.10 +/- 0.03 x 10(12) h(-1) M(circle dot), and the magnification factor for the source galaxy is 27 +/- 1. Combining the lens model with our gVriz photometry, we find a (unlensed) star formation rate (SFR) for the source galaxy of 32 h(-1) M(circle dot) yr(-1), adopting a fiducial constant SFR model with an age of 100 Myr and E(B - V) = 0.25. With an apparent magnitude of r = 19.8, this system is among the very brightest lensed z >= 2 galaxies, and provides an excellent opportunity to pursue detailed studies of the physical properties of an individual high-redshift star-forming galaxy.

• 出版日期2009-7-10