恒星反作为一个星爆星系中扩展分子外流的起源
J E Geach1, R C Hickox2, A M Diamond-Stanic3
1Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, Hertfordshire AL10 9AB, UK.
Nature
|December 5, 2014
概括
星爆星系可以通过恒星辐射压力排出大量冷分子气体,影响星系进化. 这一发现挑战了以前关于恒星反在削减恒星形成中的规模和效率的假设.
科学领域:
- 天文学和天体物理学
- 银河系的进化 银河系的进化
- 星际介质 星际介质
背景情况:
- 星爆星系通过恒星辐射压力驱动分子气体外流,限制恒星质量增长.
- 之前观察到的外流在规模 (<1 kiloparsec) 和分子气体分数上是有限的.
- 活跃的星系核可以影响外流,质疑恒星反对星系尺度的唯一影响.
研究的目的:
- 为了研究星爆能否将大量的冷分子气体推向大星系中心半径 (约. 10千帕塞克) 的时间.
- 为了确定一个巨大的星爆星系中扩展分子气体的速度和动能.
- 评估恒星辐射压力在驱动这些大规模分子外流中的作用.
主要方法:
- 在一个紧的,巨大的星爆星系中对分子气体的观测,红移0.7.
- 对从银河系中心延伸到大约10千帕塞克的气体分布的分析.
- 扩展分子气体组件的速度测量.
主要成果:
- 35%的总分子气体延伸到大约10 kiloparsecs.
- 这种扩展的气体的三分之一表现出高达每秒1000公里的速度.
- 高速气体的动能与恒星辐射压力动量流量保持一致.
结论:
- 巨大的星爆可以从银河系中心喷出大量冷分子气体.
- 恒星辐射压力能够驱动这些大量的,扩展的分子外流.
- 这些外流通过削减恒星形成和重新分配物质,显著影响银河系的进化.
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