DISCOVERY OF A VERY BRIGHT, STRONGLY LENSED z = 2 GALAXY IN THE SDSS DR5
DISCOVERY OF A VERY BRIGHT, STRONGLY LENSED z = 2 GALAXY IN THE SDSS DR5
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DOI：
10.1088/0004-637x/699/2/1242
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发表时间：
2008-09
期刊：
影响因子：
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通讯作者：
Huan Lin;E. Buckley-Geer;S. Allam;S. Allam;D. Tucker;H. Diehl;D. Kubik;Jeffrey M. Kubo;
中科院分区：
文献类型：
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作者：
Huan Lin;E. Buckley-Geer;S. Allam;S. Allam;D. Tucker;H. Diehl;D. Kubik;Jeffrey M. Kubo;
我们报告发现了一个非常明亮的 z = 2.00 恒星形成星系，该星系被前景 z = 0.422 发光红色星系 (LRG)，SDSS J120602.09+514229.5 强烈透镜化。这个绰号为“克隆”的系统是在斯隆数字巡天数据第 5 版样本中系统搜索 LRG 透镜和最亮星团星系的明亮弧时发现的。对莫纳克亚山 Subaru 8.2 m 望远镜和阿帕奇角天文台天体物理研究联盟 3.5 m 望远镜的后续观测证实了该系统的透镜性质。系统的简单透镜模型假设奇异等温椭球质量分布，在透镜红移处产生 θEin = 3.82 ± 0.″03 或 14.8 ± 0.1 h−1 kpc 的爱因斯坦半径。爱因斯坦半径内的总投影质量为 2.10 ± 0.03 × 1012 h−1 M☉，源星系的放大系数为 27 ± 1。将透镜模型与我们的 gVriz 光度测量相结合，我们发现源星系的（未透镜）恒星形成速率（SFR）为 32 h−1 M☉ yr−1，采用基准常数 SFR 模型，其中年龄为 100 Myr，E(B − V) = 0.25。该系统的视星等为 r = 19.8，是最亮的透镜 z ⩾ 2 星系之一，为对单个高红移恒星形成星系的物理特性进行详细研究提供了绝佳的机会。
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 θEin = 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 × 1012 h−1 M☉, 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☉ 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.