AN EXPONENTIAL DECLINE AT THE BRIGHT END OF THE z = 6 GALAXY LUMINOSITY FUNCTION
AN EXPONENTIAL DECLINE AT THE BRIGHT END OF THE z = 6 GALAXY LUMINOSITY FUNCTION
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DOI：
10.1088/0004-6256/145/1/4
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发表时间：
2012-02
期刊：
影响因子：
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通讯作者：
C. Willott;R. McLure;P. Hibon;R. Bielby;H. McCracken;J. Kneib;O. Ilbert;D. Bonfield;V. Bruce;M. Jarvis
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文献类型：
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作者：
C. Willott;R. McLure;P. Hibon;R. Bielby;H. McCracken;J. Kneib;O. Ilbert;D. Bonfield;V. Bruce;M. Jarvis
我们提出了一个最明亮的恒星形成星系的搜索结果，在红移z ≥ 6的基础上，加拿大-法国-夏威夷望远镜遗产调查数据。我们确定了40个莱曼破裂星系（LBG）的样本，亮度超过25.3等z′ = 4 deg 2的区域。对七个星系的光谱观测提供了四个星系的红移，其中只有两个星系有中等到强的Lyα发射线。所有四个都有明确的连续中断在其光谱。大约有一半的LBG在0.7角秒的可见光图像中被空间分辨，这表明它们的尺寸比哈勃太空望远镜发现的低光度星系要大，这可能是由于正在进行的合并。叠加的光学和红外测光与恒星质量为1010 M的星系模型一致。在2σ置信度下，最佳拟合AV = 0.75和AV > 0.48，这是大量尘埃变红的有力证据，与此时期典型的低光度无尘星系形成对比。空间范围和光谱能量分布表明，最明亮的z 106星系正在经历合并引起的恒星暴增。导出了z = 5.9恒星形成星系的光度函数。这与以前的工作一致，并显示出强有力的证据表明，在明亮的一端呈指数下降，这表明控制明亮端形状的反馈过程正在有效地发生在这个时代。
We present the results of a search for the most luminous star-forming galaxies at redshifts z ≈ 6 based on Canada–France–Hawaii Telescope Legacy Survey data. We identify a sample of 40 Lyman break galaxies (LBGs) brighter than magnitude z′ = 25.3 across an area of almost 4 deg2. Sensitive spectroscopic observations of seven galaxies provide redshifts for four, of which only two have moderate to strong Lyα emission lines. All four have clear continuum breaks in their spectra. Approximately half of the LBGs are spatially resolved in 0.7 arcsec seeing images, indicating larger sizes than lower luminosity galaxies discovered with the Hubble Space Telescope, possibly due to ongoing mergers. The stacked optical and infrared photometry is consistent with a galaxy model with stellar mass ∼1010 M☉. There is strong evidence for substantial dust reddening with a best-fit AV = 0.75 and AV > 0.48 at 2σ confidence, in contrast to the typical dust-free galaxies of lower luminosity at this epoch. The spatial extent and spectral energy distribution suggest that the most luminous z ≈ 6 galaxies are undergoing merger-induced starbursts. The luminosity function of z = 5.9 star-forming galaxies is derived. This agrees well with previous work and shows strong evidence for an exponential decline at the bright end, indicating that the feedback processes that govern the shape of the bright end are occurring effectively at this epoch.