The RMS survey: near-IR spectroscopy of massive young stellar objects
The RMS survey: near-IR spectroscopy of massive young stellar objects
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DOI：
10.1093/mnras/sts681
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发表时间：
2013-01
影响因子：
4.8
通讯作者：
H. Cooper;S. Lumsden;R. Oudmaijer;M. Hoare;A. Clarke;J. Urquhart;J. Mottram;T. Moore;B. D. U. O. Leeds;Max Planck Institute for Radioastronomy;L. Observatory;Liverpool John Moores University
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作者：
H. Cooper;S. Lumsden;R. Oudmaijer;M. Hoare;A. Clarke;J. Urquhart;J. Mottram;T. Moore;B. D. U. O. Leeds;Max Planck Institute for Radioastronomy;L. Observatory;Liverpool John Moores University
提供了 247 个天体的近红外 H 和 K 波段光谱，这些天体是从红色 MSX 源 (RMS) 调查中选择的，作为潜在的年轻恒星天体 (YSO)。 195 个（∼80%）目标是 YSO，其中 131 个是大质量 YSO（L BOL > 5×10 3 L ⊙ ，M > 8 M ⊙ ）。这是迄今为止对大质量 YSO 进行的最大规模的光谱研究，为研究大质量恒星形成提供了宝贵的资源。在本文中，我们提出了对数据的探索性分析。观察到的 YSO 具有广泛的嵌入性 (2.7 < A V < 114)，这表明这项研究涵盖了最小程度的模糊物体，一直到非常红色、多尘的来源。尽管观察到的特性多种多样，但几乎所有 YSO 都显示出一些发射线的证据。最常检测到的谱线按出现频率排列为 Brγ、H 2 、荧光 Fe ii、CO bandhead、[Fe ii] 和 He i 2-1 1 S- 1 P。总共，约 40% 的 YSO 显示出荧光 Fe ii 1.6878 μm 或 CO 带头发射（或两者），表明存在星周盘；然而，没有发现这些线的强度与测辐射热光度之间的相关性。我们还发现 ~60% 的源表现出 [Fe ii] 或 H 2 排放，表明存在流出。四分之三的排放源中含有 Brγ。 Brγ 和 H 2 发射线强度均观察到与辐射光度的良好相关性，覆盖 1 < L BOL < 3.5 × 10 5 L ⊙ 。这表明这些谱线的发射机制对于低质量、中质量和高质量 YSO 是相同的，即高质量 YSO 似乎类似于低质量 YSO 的放大版本。 © 2013 作者版权所有，由牛津大学出版社代表英国皇家天文学会出版。
Near-infrared H- and K-band spectra are presented for 247 objects, selected from the Red MSX Source (RMS) survey as potential young stellar objects (YSOs). 195 (∼80 per cent) of the targets are YSOs, of which 131 are massive YSOs (L BOL > 5×10 3 L ⊙ , M > 8 M ⊙ ). This is the largest spectroscopic study of massive YSOs to date, providing a valuable resource for the study of massive star formation. In this paper, we present our exploratory analysis of the data. The YSOs observed have a wide range of embeddedness (2.7 < A V < 114), demonstrating that this study covers minimally obscured objects right through to very red, dusty sources. Almost all YSOs show some evidence for emission lines, though there is a wide variety of observed properties. The most commonly detected lines are Brγ, H 2 , fluorescent Fe ii, CO bandhead, [Fe ii] and He i 2-1 1 S- 1 P, in order of frequency of occurrence. In total, ∼40 per cent of the YSOs display either fluorescent Fe ii 1.6878 μm or CO bandhead emission (or both), indicative of a circumstellar disc; however, no correlation of the strength of these lines with bolometric luminosity was found. We also find that ∼60 per cent of the sources exhibit [Fe ii] or H 2 emission, indicating the presence of an outflow. Three quarters of all sources have Brγ in emission. A good correlation with bolometric luminosity was observed for both the Brγ and H 2 emission line strengths, covering 1 < L BOL < 3.5 × 10 5 L ⊙ . This suggests that the emission mechanism for these lines is the same for low-, intermediate- and high-mass YSOs, i.e. high-mass YSOs appear to resemble scaled-up versions of low-mass YSOs. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.