The RMS survey: A census of massive YSO multiplicity in the K band
The RMS survey: A census of massive YSO multiplicity in the K band
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RMS 调查：K 波段大规模 YSO 多重性普查
DOI：
10.1093/mnras/stad3755
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发表时间：
2024
影响因子：
4.8
通讯作者：
Shenton R
中科院分区：
文献类型：
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作者：
Shenton R
接近100%的大质量恒星被认为是双星系统。大质量恒星的多样性似乎与它们的形成和演化有着内在的联系，而大质量年轻恒星天体（MYSO）是观测星星形成早期阶段的关键。我们已经调查了三个样本，共计数百个MYSO（）从红MSX源（RMS）目录，使用英国的红望远镜（UKIRT）红外深空巡天（UKIDSS）和Vista变量在通过Lactea（VVV）点源数据，和UKIRTK波段成像探测0.8和9弧秒（约1000-100 000 Au）之间的分离。我们使用统计方法来确定样本的二进制统计，我们发现UKIDSS样本的二进制分数为64 ± 4%，VVV样本为53 ± 4%，RMS成像样本为49 ± 8%。此外，我们使用J-和K-波段的幅度作为代理的同伴质量，和一个显着的比例检测系统的估计质量比>0.5，这表明偏离捕获形成的情况下，将与随机IMF采样。最后，我们发现，YSO位于外银河系有一个较高的二元分数比那些在内银河系。这可能是由于恒星背景密度比观测到的银河系内部低，导致视觉双星成为物理伴星的概率更高。它确实表明在探测的分离范围内有一个接近100%的二元分数，而不需要考虑选择偏差。
Close to 100 per cent of massive stars are thought to be in binary systems. The multiplicity of massive stars seems to be intrinsically linked to their formation and evolution, and massive young stellar objects (MYSOs) are key in observing this early stage of star formation. We have surveyed three samples totalling hundreds of MYSOs () across the Galaxy from the Red MSX Source (RMS) catalogue, using United Kingdom Infra-Red Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS) and Vista Variables in the Via Lactea (VVV) point source data, and UKIRTK-band imaging to probe separations between 0.8 and 9 arcsec (approx 1000–100 000 au). We have used statistical methods to determine the binary statistics of the samples, and we find binary fractions of 64 ± 4 per cent for the UKIDSS sample, 53 ± 4 per cent for the VVV sample, and 49 ± 8 per cent for the RMS imaging sample. Also, we use theJ- andK-band magnitudes as a proxy for the companion mass, and a significant fraction of the detected systems have estimated mass ratios >0.5, suggesting a deviation from the capture formation scenario which would be aligned with random IMF sampling. Finally, we find that YSOs located in the outer Galaxy have a higher binary fraction than those in the inner Galaxy. This is likely due to a lower stellar background density than observed towards the inner Galaxy, resulting in higher probabilities for visual binaries to be physical companions. It does indicate a binary fraction in the probed separation range of close to 100 per cent without the need to consider selection biases.