Quantifying the Universality of the Stellar Initial Mass Function in Old Star Clusters
Quantifying the Universality of the Stellar Initial Mass Function in Old Star Clusters
复制标题
量化老星团中恒星初始质量函数的普遍性
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
A. Sarajedini
中科院分区：
文献类型：
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作者：
N. Leigh;S. Umbreit;A. Sills;C. Knigge;G. Marchi;E. Glebbeek;A. Sarajedini
我们提出了一种新的技术来量化集群的变化，在所观察到的大样本的星星集群的恒星质量函数。我们的方法量化这些差异作为恒星质量和总集群质量的函数，并提供了一个优点，它是不敏感的质量函数的精确功能形式。我们应用我们的技术，从先进的相机调查调查球状星团，从中我们获得完整性校正的恒星质量函数的质量范围为0.25 - 0.75 M的27个集群的样本。我们的观测分析的结果进行了比较，Monte Carlo模拟球状星团的演化跨越一系列的初始质量函数，恒星总数，浓度和维里半径。我们表明，在我们的样本中的集群的现今的质量函数可以通过假设一个通用的初始质量函数的所有集群，集群到集群的差异是一致的预期从两体松弛。在未来的研究中，将需要更完整的探索初始集群条件，以更好地约束初始质量函数的精确函数形式。这项研究是第一步，使用我们的技术来约束大样本的旧银河系星星集群的动力学历史，并通过扩展，星星形成在早期宇宙。
We present a new technique to quantify cluster-to-cluster variations in the observed present-day stellar mass functions of a large sample of star clusters. Our method quantifies these differences as a function of both the stellar mass and the total cluster mass, and offers the advantage that it is insensitive to the precise functional form of the mass function. We applied our technique to data taken from the Advanced Camera for Surveys Survey for Globular Clusters, from which we obtained completeness-corrected stellar mass functions in the mass range 0.25-0.75 M⊙ for a sample of 27 clusters. The results of our observational analysis were then compared to Monte Carlo simulations for globular cluster evolution spanning a range of initial mass functions, total numbers of stars, concentrations, and virial radii. We show that the present-day mass functions of the clusters in our sample can be reproduced by assuming an universal initial mass function for all clusters, and that the cluster-to-cluster differences are consistent with what is expected from twobody relaxation. A more complete exploration of the initial cluster conditions will be needed in future studies to better constrain the precise functional form of the initial mass function. This study is a first step toward using our technique to constrain the dynamical histories of a large sample of old Galactic star clusters and, by extension, star formation in the early Universe.
影响因子：
3.2
作者：
V. Mannings;A. Boss;S. Russell
通讯作者：
V. Mannings;A. Boss;S. Russell