Radii of young star clusters in nearby galaxies
Radii of young star clusters in nearby galaxies
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附近星系中年轻星团的半径
DOI：
10.1093/mnras/stab2907
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发表时间：
2021
影响因子：
4.8
通讯作者：
Gnedin, Oleg Y
中科院分区：
文献类型：
--
作者：
Brown, Gillen;Gnedin, Oleg Y
我们测量了Legacy Extragalactic UV Survey（LEGUS）中31个星系中年轻星星团的投影半光半径。我们实现了一个定制的管道，专门设计用于防止污染，这使我们能够测量6097个集群的半径。这是目前可获得的最大的年轻星星星团半径样本。我们发现，大多数（但不是所有）星系共享一个共同的集群半径分布，在3 pc左右的峰值。我们发现了一个清晰的质量-半径关系，其形式为Reff <$M0.24。这种关系存在于所有年龄小于1 Gyr的星团，但年龄小于10 Myr的星团的斜率较浅。我们提出了简单的玩具模型来解释这些年龄趋势，发现高质量的集群更有可能不受潮汐限制和扩大。我们还发现，大多数集群在LEGUS的引力约束，特别是在年龄较大或更高的质量。最后，我们提出了集群密度和表面密度分布，发现一个大的分散，似乎随着集群年龄的减少。最年轻的星团的典型表面密度为100。
We measure the projected half-light radii of young star clusters in 31 galaxies from the Legacy Extragalactic UV Survey (LEGUS). We implement a custom pipeline specifically designed to be robust against contamination, which allows us to measure radii for 6097 clusters. This is the largest sample of young star cluster radii currently available. We find that most (but not all) galaxies share a common cluster radius distribution, with the peak at around 3 pc. We find a clear mass–radius relation of the formReff∝M0.24. This relation is present at all cluster ages younger than 1 Gyr, but with a shallower slope for clusters younger than 10 Myr. We present simple toy models to interpret these age trends, finding that high-mass clusters are more likely to be not tidally limited and expand. We also find that most clusters in LEGUS are gravitationally bound, especially at older ages or higher masses. Lastly, we present the cluster density and surface density distributions, finding a large scatter that appears to decrease with cluster age. The youngest clusters have a typical surface density of 100.