A massive protocluster of galaxies at a redshift of z ≈ 5.3
A massive protocluster of galaxies at a redshift of z ≈ 5.3
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DOI：
10.1038/nature09681
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发表时间：
2011-01
期刊：
影响因子：
64.8
通讯作者：
P. Capak;D. Riechers;N. Scoville;C. Carilli;P. Cox;R. Neri;B. Robertson;M. Salvato;E. Schinnerer-E.-S
中科院分区：
文献类型：
--
作者：
P. Capak;D. Riechers;N. Scoville;C. Carilli;P. Cox;R. Neri;B. Robertson;M. Salvato;E. Schinnerer-E.-S
大质量的星系团被发现可以追溯到大爆炸后39亿年（3.9 Gyr;z= 1.62），其中包含在更早的时代形成的恒星。使用当前的冷暗物质模型进行的宇宙学模拟预测，这些系统应该是从“原星系团”发展而来的，原星系团是早期高密度的大质量星系，它们分层合并形成一个星系团。这些原星系团区域本身是按等级建立的，因此预计将包含极其巨大的星系，可以观察到发光的类星体和星暴。然而，这张照片的观测证据是稀疏的，因为高红移原星团是罕见的，难以观察。在这里，我们报告了一个可以追溯到大爆炸后1 Gyr（z= 5.3）的原星系团区域。这个巨大的星系团延伸超过13兆秒差距，包含一个发光的类星体以及一个富含分子气体的系统。这些巨大的星系在这个区域中放置了超过4 × 1011太阳质量的暗物质和发光物质的下限，这与宇宙学模拟对最早的星系团的预期一致。
Massive clusters of galaxies have been found that date from as early as 3.9 billion years (3.9 Gyr;z= 1.62) after the Big Bang, containing stars that formed at even earlier epochs,. Cosmological simulations using the current cold dark matter model predict that these systems should descend from ‘protoclusters’—early overdensities of massive galaxies that merge hierarchically to form a cluster,. These protocluster regions themselves are built up hierarchically and so are expected to contain extremely massive galaxies that can be observed as luminous quasars and starbursts,,. Observational evidence for this picture, however, is sparse because high-redshift protoclusters are rare and difficult to observe,. Here we report a protocluster region that dates from 1 Gyr (z= 5.3) after the Big Bang. This cluster of massive galaxies extends over more than 13 megaparsecs and contains a luminous quasar as well as a system rich in molecular gas. These massive galaxies place a lower limit of more than 4 × 1011solar masses of dark and luminous matter in this region, consistent with that expected from cosmological simulations for the earliest galaxy clusters,,.