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一个星系在红移z = 8.6的光谱确认
M D Lehnert1, N P H Nesvadba, J-G Cuby
1GEPI, Observatoire de Paris, CNRS, Université Paris Diderot, 5 Place Jules Janssen, 92190 Meudon, France. matthew.lehnert@obspm.fr
Nature
|October 22, 2010
概括
天文学家发现了来自大爆炸后不到6亿年的星系的莱曼-α (Lyα) 光子. 这个星系,红移z=8.5549,为早期宇宙提供了关键的见解.
科学领域:
- 宇宙学和银河系外天文学.
- 早期宇宙研究研究 早期宇宙研究
- 银河系的进化和再电离.
背景情况:
- 原始星系中的第一颗恒星通过电离星际介质对宇宙产生了重大影响.
- 重离子化是一个复杂的过程,在大爆炸 (红移 z ≈ 6) 后大约10亿年完成.
- 来自遥远星系的电离光子的检测限制了负责再电离的来源.
研究的目的:
- 为了检测来自早期宇宙中的星系的莱曼-α (Lyα) 光子.
- 对再电离源的时间,位置和性质进行限制.
- 为了确定在研究时已知的最遥远的星系.
主要方法:
- 观测和检测来自星系的莱曼-α (Lyα) 辐射线.
- 谱分析以确定红移和距离.
- 与先前已知的最远物体进行比较.
主要成果:
- 来自银河系UDFy-38135539的Lyα光子在z = 8.5549 ± 0.0002.2.的红移下被检测到.
- 这个星系是目前已知的最遥远的物体,在大爆炸后不到6亿年观察到.
- 检测到的单一来源不足以电离出 Lyα 逃逸所需的体积,这意味着来自附近较弱星系的贡献.
结论:
- 检测到的星系提供了早期星系形成的证据,以及其在宇宙再电离化中的作用.
- 再电离可能涉及众多,可能较弱的星系的集体贡献.
- 需要进一步的观测才能充分理解再离子化过程以及微弱星系群体的贡献.
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