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arXiv 0909.4317astro-ph.GAastro-ph.SR
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星团瓦解

Star cluster disruption

M. Gieles

摘要:

星团通常被用作外部星系中主要恒星形成事件的示踪剂,因为它们可以比单个恒星更远的距离进行研究。理解它们的演化是至关重要的,如果它们被用来推导,例如,它们的宿主星系的恒星形成历史。更具体地说,我们想知道集群的生命周期如何取决于它们的环境和结构属性,如质量和半径。这篇综述从理论上概述了星团的早期演化以及由此产生的长期生存机会。这表明,初始密度大于10^4 Msun pc-3的团簇在气体排出或"婴儿死亡"阶段存活下来。在~1000万年前,它们是束缚的,密度为10 ^{3 +/-1} Msun pc-3。在这段时间之后,它们是稳定的,不会因恒星演化而膨胀,遇到巨大的分子云,如果它们处于中等潮汐场中,很可能会再生存一个哈勃时间。初始密度较低的星团(<100 Msun pc-3)将在几十万年内分散到磁场中。一些讨论是如何额外的星系星团的人口,特别是他们的年龄分布可以用来获得洞察力中断。

英文摘要:

Star clusters are often used as tracers of major star formation events in external galaxies as they can be studied up to much larger distances than individual stars. It is vital to understand their evolution if they are used to derive, for example, the star formation history of their host galaxy. More specifically, we want to know how cluster lifetimes depend on their environment and structural properties such as mass and radius. This review presents a theoretical overview of the early evolution of star clusters and the consequent long term survival chances. It is suggested that clusters forming with initial densities of >10^4 Msun pc-3 survive the gas expulsion, or "infant mortality", phase. At ~10 Myr they are bound and have densities of 10^{3+/-1} Msun pc-3. After this time they are stable against expansion by stellar evolution, encounters with giant molecular clouds and will most likely survive for another Hubble time if they are in a moderate tidal field. Clusters with lower initial densities (<100 Msun pc-3) will disperse into the field within a few 10s of Myrs. Some discussion is provided on how extra galactic star cluster populations and especially their age distributions can be used to gain insight in disruption.

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。

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