云核质量函数

发布时间：2018-04-28 05:21

本文选题：恒星形成 + 云核　；参考：《天文学进展》2014年03期

【摘要】：云核质量函数(CMF)是分子云中致密云核的一个基本观测性质,被用来研究恒星的初始质量函数(IMF)的成因。CMF可以用积分和微分两种形式来表达。样本较小时,积分形式的CMF拟合出的结果能够清晰地反映出云核的数目;样本较大时,微分形式的CMF可以合并数据明确地表述CMF。一般来说,CMF有幂律和正态对数两种函数形式。在湍流存在的情况下,正态对数函数可以更好地拟合CMF;幂律形式的CMF谱指数在一定范围内波动,其大小与天区和样本有关。Salpeter提出恒星的初始质量函数(IMF)是一个幂律函数,很多研究认为CMF与IMF是相似的。而近期的一些研究工作认为CMF与IMF是不相同的,这主要有三方面的原因:(1)用一个具体的幂律函数去拟合一个任意的积分函数是不可靠的;(2)只有当M Mmax(或者Mmax-→∞)时,积分形式的CMF可以近似地认为是幂律形式的;(3)采用Monte Carlo方法拟合CMF能够增加拟合结果的可信度。
[Abstract]:Cloud kernel mass function (CMF) is a basic observational property of dense cloud nuclei in molecular clouds. It is used to study the origin of the initial mass function (IMF) of stars. CMF can be expressed in two forms: integral and differential. When the sample is small, the result of CMF fitting in integral form can clearly reflect the number of cloud kernels, and when the sample is large, the CMF in differential form can clearly express the number of cloud kernels. Generally speaking, the CMF has two function forms: power law and normal logarithm. In the presence of turbulence, the normal logarithmic function can better fit the CMF spectrum exponent in the form of power law, which fluctuates in a certain range, and the magnitude of which is related to the sky region and the sample. Salpeter suggests that the initial mass function of a star is a power law function. Many studies suggest that CMF and IMF are similar. Some recent studies have suggested that CMF and IMF are different. This is mainly for three reasons: 1) it is unreliable to fit an arbitrary integral function with a specific power law function. The integral form of CMF can be considered as a power law form approximately. The fitting of CMF with Monte Carlo method can increase the reliability of the fitting results.
【作者单位】：中国科学院国家天文台;中国科学院射电天文重点实验室;中国科学院大学;
【基金】：973项目(2012CB821802) 国家自然科学基金(11373038) 中国科学院战略性先导科技专项(B类)(XDB09000000)
【分类号】：P152

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