论文标题
阿尔玛（Alma
ALMA Observations of Massive Clouds in the Central Molecular Zone: Jeans Fragmentation and Cluster Formation
论文作者
论文摘要
我们报告了ALMA条带6的连续观测值2000 AU在银河系中央分子区域中朝着四个巨大的分子云分辨率分辨率。为了研究气体碎片化，我们使用树状图方法来识别粉尘连续发射所追踪的核心。尽管在云比例尺上具有相似的质量（$ \ sim $ 1--5 PC），但这四个云在观察到的分辨率下表现出不同的片段化状态。假设恒定的尘埃温度为20 K，我们构建了云的核心质量功能，并且与规范初始质量函数相比，发现了略有最高的形状，但是我们注意到几种可能影响该结果的明显不确定性。最小跨越树方法所标识的内核之间的特征空间分离，$ \ sim $$ 10^4 $ au和特征性的核心质量（1--7 $ m_ \ odot $）与热牛仔裤碎片的预测一致。显示碎片的三个云可能是形成OB关联（恒星质量$ \ sim $$ 10^3 $ $ m_ \ odot $）。当前正在调查的四个云中似乎都没有能够形成诸如拱门和quintuplet（$ \ sim $$ 10^4 $ $ $ m_ \ odot $）之类的巨大星团，但是它们可能会通过进一步的加油在核心上形成此类簇。
We report ALMA Band 6 continuum observations of 2000 AU resolution toward four massive molecular clouds in the Central Molecular Zone of the Galaxy. To study gas fragmentation, we use the dendrogram method to identify cores as traced by the dust continuum emission. The four clouds exhibit different fragmentation states at the observed resolution despite having similar masses at the cloud scale ($\sim$1--5 pc). Assuming a constant dust temperature of 20 K, we construct core mass functions of the clouds and find a slightly top-heavy shape as compared to the canonical initial mass function, but we note several significant uncertainties that may affect this result. The characteristic spatial separation between the cores as identified by the minimum spanning tree method, $\sim$$10^4$ AU, and the characteristic core mass, 1--7 $M_\odot$, are consistent with predictions of thermal Jeans fragmentation. The three clouds showing fragmentation may be forming OB associations (stellar mass $\sim$$10^3$ $M_\odot$). None of the four clouds under investigation seem to be currently able to form massive star clusters like the Arches and the Quintuplet ($\sim$$10^4$ $M_\odot$), but they may form such clusters by further gas accretion onto the cores.
