Gravothermal oscillations in two-component models of star clusters
Gravothermal oscillations in two-component models of star clusters
复制标题
星团二元模型中的重力热振荡
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
D. Heggie
中科院分区：
文献类型：
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作者：
Philip G. Breen;D. Heggie
本文研究了具有不同质量比和总质量比的双组分星系团的重力热振荡。重力热振荡首次出现的恒星的临界数量是使用气体代码。研究了振荡的本质，结果表明，由于质量分离，可以通过关注较重组分的行为来理解振荡。有人认为，在每一个振荡，在较大的半径开始，而核心仍在扩大的集群的消隐。这种引力衰减可以阻止和逆转重力热驱动的膨胀。核心外的物质收缩，因为它将能量损失给冷膨胀的核心和更大半径的物质。每个模型的核心崩溃时间也被发现和讨论。对于一个适当选择的情况下，直接N体运行进行，以检查从气体模型中获得的结果，包括证据的重力热性质的振荡和温度反演驱动的膨胀。
In this paper, gravothermal oscillations are investigated in two-component clusters with a range of different stellar mass ratios and total component mass ratios. The critical number of stars at which gravothermal oscillations first appeared is found using a gas code. The nature of the oscillations is investigated and it is shown that the oscillations can be understood by focusing on the behaviour of the heavier component because of mass segregation. It is argued that, during each oscillation, the recollapse of the cluster begins at larger radii while the core is still expanding. This recollapse can halt and reverse a gravothermally driven expansion. This material outside the core contracts because it is losing energy both to the cool expanding core and to the material at larger radii. The core-collapse times for each model are also found and discussed. For an appropriately chosen case, direct N-body runs were carried out, in order to check the results obtained from the gas model, including evidence of the gravothermal nature of the oscillations and the temperature inversion that drives the expansion.