一个候选红移z ≈ 10星系和在500 Myr的年龄快速变化的人口
R J Bouwens1, G D Illingworth, I Labbe
1Department of Astronomy, University of California Santa Cruz, Santa Cruz, California 95064, USA. bouwens@ucolick.org
Nature
|January 29, 2011
概括
天文学家使用哈勃超深场数据搜索早期星系. 他们发现了一个可能的星系的红移值为~10,这表明早期宇宙中星系的快速增长.
科学领域:
- 太空进化的宇宙进化
- 银河系形成的形成
- 早期宇宙天体物理学 天体物理学
背景情况:
- 在红移3-6的6000多个星系已被确定,存在于大爆炸后的9亿至2亿年.
- 哈勃超深场 (HUDF09) 已经提供了红移约8的星系的检测,这些是最早发现的物体.
- 之前的观测表明,显著的恒星形成发生在红移大于9-10时.
研究的目的:
- 为了进行超深度搜索红移10的星系,大约在大爆炸后5亿年.
- 为了研究在再电离时代的恒星形成率密度.
- 要了解红移10~8.0之间星系的快速形成.
主要方法:
- 使用完整的两年HUDF09数据集进行深入分析.
- 进行超深度搜索,以红移约10.0的速度寻找候选星系.
- 分析基于源检测和非检测的恒星形成率密度.
主要成果:
- 一个潜在的星系候选者在红移~10被确定.
- 在红移10时的恒星形成率密度大约是红移8.8时的10%左右.
- 从红移10到8.8观察到星系的亮度密度和体积密度显著增加.
结论:
- 银河系的积聚在红移10到8.0之间非常快.
- 红移前1亿至2亿年的时间是最早星系形成的关键时期.
- 这些发现提供了关于再电离时代星系形成的关键见解.
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