Core Mass Function: The Role of Gravity
Core Mass Function: The Role of Gravity
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DOI：
10.1086/588608
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发表时间：
2008-01
期刊：
影响因子：
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通讯作者：
S. Dib;A. Brandenburg;Jongsoo Kim;M. Gopinathan;P. André
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文献类型：
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作者：
S. Dib;A. Brandenburg;Jongsoo Kim;M. Gopinathan;P. André
我们分析了在等温，磁化，湍流和自引力近临界分子云模型中形成的核的质量分布。在两个密度阈值水平下识别核心。我们的主要结果是，自引力的存在修改的斜率的核心质量函数（CMF）在高质量端。在低阈值时，斜率比纯湍流破碎预测的要小。斜坡变浅是由于岩心聚结和天然气聚集的影响。最重要的是，在高质量端的CMF的斜率变陡时，核心选择在更高的密度阈值，或者，如果CMF是一个对数正态函数拟合，对数正态分布的宽度随着阈值的增加而减小。这是由于这样的事实，即重力起着更重要的作用，在更高的密度阈值所选择的更密集的结构，并导致的结论，重力的作用是必不可少的，在产生一个CMF承担更多的相似性，IMF的核心时，选择了一个增加的密度阈值的观测。
We analyze the mass distribution of cores formed in an isothermal, magnetized, turbulent, and self-gravitating nearly critical molecular cloud model. Cores are identified at two density threshold levels. Our main results are that the presence of self-gravity modifies the slopes of the core mass function (CMF) at the high-mass end. At low thresholds, the slope is shallower than the one predicted by pure turbulent fragmentation. The shallowness of the slope is due to the effects of core coalescence and gas accretion. Most importantly, the slope of the CMF at the high-mass end steepens when cores are selected at higher density thresholds, or alternatively, if the CMF is fitted with a lognormal function, the width of the lognormal distribution decreases with increasing threshold. This is due to the fact that gravity plays a more important role in denser structures selected at higher density threshold and leads to the conclusion that the role of gravity is essential in generating a CMF that bears more resemblance to the IMF when cores are selected with an increasing density threshold in the observations.