Detection of an oxygen emission line from a high-redshift galaxy in the reionization epoch
Detection of an oxygen emission line from a high-redshift galaxy in the reionization epoch
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DOI：
10.1126/science.aaf0714
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发表时间：
2016-06
期刊：
影响因子：
56.9
通讯作者：
A. Inoue;Y. Tamura;H. Matsuo;K. Mawatari;I. Shimizu;T. Shibuya;K. Ota;N. Yoshida;E. Zackrisson;N. Kashikawa;K. Kohno;H. Umehata;B. Hatsukade;M. Iye;Y. Matsuda;T. Okamoto;Y. Yamaguchi
中科院分区：
文献类型：
--
作者：
A. Inoue;Y. Tamura;H. Matsuo;K. Mawatari;I. Shimizu;T. Shibuya;K. Ota;N. Yoshida;E. Zackrisson;N. Kashikawa;K. Kohno;H. Umehata;B. Hatsukade;M. Iye;Y. Matsuda;T. Okamoto;Y. Yamaguchi
在早期宇宙中闪耀着明亮的光芒在宇宙历史早期形成的银河系是紫外线辐射的强大来源。这种辐射在“再电离时期”电离了周围的星系际介质。井上等人在一个星系中探测到了原子发射谱线的高红移--当时的宇宙只有现在年龄的5%（参见De Breuck的《透视》）。来自光学、红外和亚毫米天文台的数据确定了它的气体和尘埃含量以及它发射的紫外线辐射量。以这种方式研究类似的星系将使天文学家能够确定第一个星系是如何形成、演化和影响周围环境的。早期宇宙中一个明亮的星系发出大量的紫外线辐射。宇宙再电离过程中星系中星际介质的物理性质和元素丰度对于理解星系在这一过程中的作用非常重要。我们报告了阿塔卡马大型毫米/亚毫米阵列探测到的氧发射线在88微米的波长从一个星系在大爆炸后约7亿年的时代。这个星系的氧丰度估计约为太阳的十分之一。没有探测到远红外连续辐射表明银河系中星际尘埃的缺乏。在158微米波长处的碳排放线也没有被检测到，这意味着中性气体的数量异常少。这些特性可能允许电离光子逃逸到星系际介质中。
Shining brightly in the early universe Galaxies that formed early in the history of the universe were powerful sources of ultraviolet radiation. This radiation ionized the surrounding intergalactic medium during the “epoch of reionization.” Inoue et al. detected atomic emission lines from a galaxy at high redshift—seen as it was when the universe was only ~5% of its current age (see the Perspective by De Breuck). Data from optical, infrared, and submillimeter observatories determined its gas and dust content and the amount of ultraviolet radiation it emitted. Studying similar galaxies in such a manner will allow astronomers to determine how the first galaxies formed, evolved, and influenced their surroundings. Science, this issue p. 1559; see also p. 1520 A galaxy shining brightly in the early universe emits copious ultraviolet radiation. The physical properties and elemental abundances of the interstellar medium in galaxies during cosmic reionization are important for understanding the role of galaxies in this process. We report the Atacama Large Millimeter/submillimeter Array detection of an oxygen emission line at a wavelength of 88 micrometers from a galaxy at an epoch about 700 million years after the Big Bang. The oxygen abundance of this galaxy is estimated at about one-tenth that of the Sun. The nondetection of far-infrared continuum emission indicates a deficiency of interstellar dust in the galaxy. A carbon emission line at a wavelength of 158 micrometers is also not detected, implying an unusually small amount of neutral gas. These properties might allow ionizing photons to escape into the intergalactic medium.