论文标题
阿尔玛（Alma
ALMA observations of the early stages of substellar formation in the Lupus 1 and 3 molecular clouds
论文作者
论文摘要
导致棕矮星（BDS）形成的主要机制仍然不确定。从年轻物体（前BD核心和原始BDS）获得的地层的最直接密钥受到可用数量统计数字的限制。我们的目的是识别和表征狼疮1和3分子云中的一组前和原始BDS以及II类BDS，以测试其形成机制。我们对先前从阿兹台克/ASTE数据（1.1 mm）的64个核心的选择进行了ALMA带6（1.3 mm）连续观测，以及狼疮1和3分子云中先前已知的II类BDS。光学中调查的档案数据用于补充这些观察结果。我们期望这些ALMA观察结果有效地检测这些区域中最年轻的来源，因为它们探测了这些源散发出大部分辐射的频域。我们从15个Alma领域检测到了19个来源。考虑到我们观察到的设置中的所有指数，Alma检测率为$ \ sim $ 23％，并且检测到的来源的派生质量在$ \ sim $ 0.18和124 $ \ mathrm {m_ {jup}} $之间。我们根据这些源的光谱能量分布将这些来源分类为5个II类资源，2个新的I/0类候选者以及12个新的可能的Pre-BD或深层嵌入的Protostellar候选者。我们检测到了一个有希望的候选者，用于0/I Proto-BD源，并推断出真正的II类BD的磁盘尘埃质量。 BD前核可能是正在进行的大规模崩溃过程的副产品。 II类BD磁盘遵循在低质量恒星状态下观察到的磁盘质量与中心对象的质量之间的相关性。我们得出的结论是，尽管磁盘碎片可能导致了相当一部分的BDS，但样本中的来源很可能被形成为低质量恒星形成的缩放版本。
The dominant mechanism leading to the formation of brown dwarfs (BDs) remains uncertain. The most direct keys to formation, which are obtained from younger objects (pre-BD cores and proto-BDs), are limited by the very low number statistics available. We aim to identify and characterize a set of pre- and proto-BDs as well as Class II BDs in the Lupus 1 and 3 molecular clouds to test their formation mechanism. We performed ALMA band 6 (1.3 mm) continuum observations of a selection of 64 cores previously identified from AzTEC/ASTE data (1.1 mm), along with previously known Class II BDs in the Lupus 1 and 3 molecular clouds. Surveyed archival data in the optical were used to complement these observations. We expect these ALMA observations prove efficient in detecting the youngest sources in these regions, since they probe the frequency domain at which these sources emit most of their radiation. We detected 19 sources from 15 ALMA fields. Considering all the pointings in our observing setup, the ALMA detection rate was $\sim$23% and the derived masses of the detected sources were between $\sim$0.18 and 124 $\mathrm{M_{Jup}}$. We classified these sources according to their spectral energy distribution as 5 Class II sources, 2 new Class I/0 candidats, and 12 new possible pre-BD or deeply embedded protostellar candidates. We detected a promising candidate for a Class 0/I proto-BD source and inferred the disk dust mass of a bona fide Class II BD. The pre-BD cores might be the byproduct of an ongoing process of large-scale collapse. The Class II BD disks follow the correlation between disk mass and the mass of the central object that is observed at the low-mass stellar regime. We conclude that it is highly probable that the sources in the sample are formed as a scaled-down version of low-mass star formation, although disk fragmentation may be responsible for a considerable fraction of BDs.
