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一个发光的类星体,红移值为z=7.0855
Daniel J Mortlock1, Stephen J Warren, Bram P Venemans
1Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, UK. mortlock@ic.ac.uk)
Nature
|July 2, 2011
概括
天文学家发现了一个类星体 (ULAS J1120+0641) 红移7.085,为早期宇宙提供了新的见解. 这一发现有助于探测星际介质.
科学领域:
- 宇宙学的宇宙学是什么?
- 天体物理学 天体物理学
- 早期宇宙研究 早期宇宙研究
背景情况:
- 星系间介质 (IGM) 在大爆炸后的10亿年之前才完全重新离子化.
- 由于光学调查的局限性,观测红移 (z) > 6.5 的类星体具有挑战性.
- 之前的研究依赖于z < 6.5的类星体来理解再电离.
研究的目的:
- 识别和描述具有更高红移 (z>6.5) 的类星体,以探测IGM.
- 为了研究早期宇宙和再电离时代的属性.
- 为了理解宇宙黎明时的IGM中性分数.
主要方法:
- 利用光学调查来识别高红移类星候选者.
- 对ULAS J112001.48+064124.3 (z=7.085) 进行了光谱观测.
- 分析了类星体的亮度,黑洞质量和近区域的电离半径.
主要成果:
- 在红移z=7.085时发现ULAS J1120+0641,这对应于大爆炸后的0.77亿年.
- 测量了6.3 × 10^13 L 的亮度和2 × 10^9 M 的黑洞质量.
- 观测到近区域半径为1.9兆帕塞克,比z ~ 6.0-6.4类星体典型的小.
- 接近区域的传输形状表明Lyα减压翼,这表明前景IGM中中性分数>0.1.
结论:
- ULAS J1120+0641提供了在z ~ 7.0的IGM的关键探测器.
- 较小的离子近区域和Lyα缓冲翼表明早期IGM中显著的中性.
- 这一发现推动了研究再电离时代的观测前沿.
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