arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2501.01035astro-ph.GAastro-ph.SR
收藏

恒星角动量反映恒星形成环境与银河系演化历史之间的关系

The angular momentum of stars reflects the relationship between star-forming environment and galactic evolution history

Yu-Fu Shen, Yan Xu, Yi-Bo Wang, Xiu-Lin Huang, Xing-Xing Hu, Qi Yuan

AI总结:

本文利用开普勒场中质量超过克拉夫特断裂点的恒星角动量数据,发现1.4至1.8倍太阳质量恒星的角动量与年龄呈反比,提出该关系反映了银河系恒星形成环境的演化,并为初始质量函数变化提供解释。

摘要:

本研究聚焦于开普勒天区中质量超过克拉夫特断裂点的恒星。这些恒星的旋转角动量与它们在零龄主序阶段时的角动量基本相同。这些恒星在前主序阶段经历的角动量耗散也相对较弱,因此它们的旋转角动量能够反映其母分子云的参数。基于观测数据中恒星在拐点前后表现出的角动量守恒现象,我们评估了角动量测量的可靠性。我们发现,质量在1.4倍太阳质量到1.8倍太阳质量之间的恒星,其角动量与等龄线年龄之间呈现反比关系。我们提出,角动量与年龄的相关性反映了银河系历史中恒星形成环境的变化。此外,观测到的反比关系意味着,随着银河系的演化,在其中形成的恒星倾向于拥有更大的旋转角动量。这一趋势会促进恒星在前主序阶段发生碎裂,并抑制大质量恒星的形成,从而为解释初始质量函数的变化提供了一个有用的视角。

英文摘要:

This study focuses on stars with masses above the Kraft break in the \textit{Kepler} field. Their rotational angular momenta are essentially the same as those at the zero-age main sequence. The angular momentum dissipation experienced by these stars during their pre-main sequence phase is also relatively weak, so their rotational angular momentum can reflect the parameters of their parental molecular clouds. The reliability of angular momentum measurements was evaluated based on the phenomenon of angular momentum conservation observed in stars before and after the turn-off point in observational data. We find that stars with masses between 1.4$M_\odot$ and 1.8$M_\odot$ show an inverse proportionality between angular momentum and isochrone age. We propose that the angular momentum-age correlation reflects changes in the star-forming environment in the Milky Way's history. Besides, the observed inverse proportionality implies that, as the Milky Way has evolved, the stars formed within it tend to possess greater rotational angular momenta. This trend would promote the fragmentation of stars during the pre-main sequence phase and inhibit the formation of massive stars, providing a useful perspective for explaining variations in the initial mass function.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑