在恒星形成过程中,在多个长度尺度上对自身重力的作用
Alyssa A Goodman1, Erik W Rosolowsky, Michelle A Borkin
1Initiative in Innovative Computing at Harvard, Cambridge, Massachusetts 02138, USA. agoodman@cfa.harvard.edu
Nature
|January 6, 2009
概括
自重力对于分子云中的恒星形成至关重要. 对L1448云的分析表明,自我引力在各种尺度上显著影响恒星形成,特别是对于恒星前核心.
科学领域:
- 天体物理学 天体物理学
- 星星形成 星星形成
- 计算天体物理学 计算天体物理学
背景情况:
- 众所周知,在恒星形成的后期阶段,自我引力至关重要,它驱使密集的核心崩成恒星加盘系统.
- 在分子云的早期阶段和更大的尺度 (例如,~1 帕塞克) 中,自我引力的作用仍然不确定.
- 一些模拟表明,流分裂本身可以建立恒星初始质量函数,而不考虑自身重力.
研究的目的:
- 为了研究在恒星形成过程中的分子云在各种尺度上的自我引力的作用.
- 为了分析L1448分子云,使用树图分析来识别自我引力结构.
- 将观测结果与包括或排除自身重力的模拟进行比较.
主要方法:
- 在L1448分子云的观测数据上使用了树状图 (层次树状图) 分析,该云由 (13) CO.
- 分析了尘埃排放峰值,以确定紧的恒星前核心.
- 将观测结果与缺乏自身重力的模拟的树图分析进行了比较.
主要成果:
- 自重力在L1448分子云中观察到的尺度中起着重要作用,尽管不均.
- 超过90%的前恒星核心位于由树图分析识别的自我引力结构中.
- 没有自身引力的模拟,虽然模仿了一些观察到的光谱,但显示出比观察到的更大比例的气体似乎具有自身引力.
结论:
- 一个自我引力似乎是存在前恒星核心和形成恒星的关键条件.
- 在"非自引"模拟中重力的重要作用表明其假设和输出中的潜在不一致性.
- 包括自身重力在内,对于在亚帕塞克尺度上对恒星形成的真实模拟至关重要.
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