两颗发光星系在红移14的光谱确认
Stefano Carniani1, Kevin Hainline2, Francesco D'Eugenio3,4
1Scuola Normale Superiore, Pisa, Italy. stefano.carniani@sns.it.
Nature
|July 29, 2024
概括
詹姆斯·韦伯太空望远镜 (JWST) 证实了两个发光的星系在红移z=13.9,大爆炸后仅存在3亿年. 这些早期星系挑战了当前的宇宙进化模型.
科学领域:
- 宇宙学
- 银河系的演变
- 观测天文学
背景情况:
- 詹姆斯·韦伯太空望远镜 (JWST) 的观测发现了许多高红移的星系 (z ≈ 13),表明了星系的快速发展.
- 许多早期的候选星系缺乏光谱证据,使它们的距离和属性不确定.
- 这与早期星系形成的标准宇宙模型存在潜在的紧张关系.
研究的目的:
- 提供光谱证实高红移的发光星系.
- 准确确定这些早期星系的距离和属性.
- 测试早期发光星系是否可以通过黑洞积聚或恒星辐射来解释.
主要方法:
- 使用近红外光谱仪 (NIRSpec) 的JWST先进深度超星系调查 (JW-ADES).
- 在z ≈ 13获得两个候选发光星系的光谱.
- 分析了光谱特征,包括紫外线连续和莱曼α断裂,以确认红移和属性.
主要成果:
- 在z = 13.90 ± 0.17的两个发光星系的光谱确认.
- 星系呈现紫外线连续性与莱曼α断裂,但没有辐射线.
- 最遥远的星系是出乎意料的明亮和空间分辨率 (半径260帕塞克).
- 这两个星系都有的紫外线倾斜,表明恒星连续辐射占主导地位.
结论:
- 在大爆炸后的3亿年里, 存在着发光的星系.
- 这些早期发光星系的数量超过了以前的预期.
- 观察到的属性表明恒星发射, 而不是黑洞积聚, 主导着这些早期星系.
- 星系形成模型需要修改以适应早期宇宙中如此庞大和发光的星系.
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