A SPITZER-SELECTED GALAXY CLUSTER AT z = 1.62
A SPITZER-SELECTED GALAXY CLUSTER AT z = 1.62
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DOI：
10.1088/0004-637x/716/2/1503
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发表时间：
2010-02
期刊：
影响因子：
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通讯作者：
C. Papovich;I. Momcheva;C. Willmer;K. Finkelstein;S. Finkelstein;K. Tran;M. Brodwin;J. Dunlop
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文献类型：
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作者：
C. Papovich;I. Momcheva;C. Willmer;K. Finkelstein;S. Finkelstein;K. Tran;M. Brodwin;J. Dunlop
我们报告的星系团的发现z = 1.62位于斯皮策广域红外河外巡天XMM-LSS领域。这个结构被选中仅仅是因为红色斯皮策/红外线阵列相机颜色的星系密度过高，（[3.6]-[4.5]）AB>-0.1磁等。来自斯巴鲁XMM深度巡天的光度红移（BViz波段），UKIRT红外深测-超深测（UKIDSS-UDS，JK波段）和斯皮策公共UDS巡天（3.6-8.0 μm）显示，这个星系团对应于z = 1.6的星系表面密度，比这个红移的平均值高出20σ。我们用麦哲伦望远镜上的IMACS获得了星系团区域星系的光谱观测。我们在z = 1.62-1.63的范围内测量了7个星系的红移，在2.8弧分（1.7 mag.的光度红移概率分布的红色星系强烈的峰值在z = 1.62，符合光谱确认的星系。红色序列上星系的静止坐标系（U − B）颜色和散射与平均光度加权年龄1.2 ± 0.1 Gyr一致，产生了形成红移，对应于这些星系中最后一个重要的星星形成时期。
We report the discovery of a galaxy cluster at z = 1.62 located in the Spitzer Wide-Area Infrared Extragalactic survey XMM–LSS field. This structure was selected solely as an overdensity of galaxies with red Spitzer/Infrared Array Camera colors, satisfying ([3.6] − [4.5])AB> − 0.1 mag. Photometric redshifts derived from the Subaru XMM Deep Survey (BViz bands), the UKIRT Infrared Deep Survey–Ultra-Deep Survey (UKIDSS–UDS, JK bands), and from the Spitzer Public UDS survey (3.6–8.0 μm) show that this cluster corresponds to a surface density of galaxies at z ≈ 1.6 that is >20σ above the mean at this redshift. We obtained optical spectroscopic observations of galaxies in the cluster region using IMACS on the Magellan telescope. We measured redshifts for seven galaxies in the range z = 1.62–1.63 within 2.8 arcmin (1.7 mag. The photometric-redshift probability distributions for the red galaxies are strongly peaked at z = 1.62, coincident with the spectroscopically confirmed galaxies. The rest-frame (U − B) color and scatter of galaxies on the red sequence are consistent with a mean luminosity-weighted age of 1.2 ± 0.1 Gyr, yielding a formation redshift , and corresponding to the last significant star formation period in these galaxies.