A spectroscopic survey on the multiplicity of high-mass stars
A spectroscopic survey on the multiplicity of high-mass stars
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DOI：
10.1111/j.1365-2966.2012.21317.x
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发表时间：
2012-05
影响因子：
4.8
通讯作者：
R. Chini;V. Hoffmeister;A. Nasseri;O. Stahl;H. Zinnecker
中科院分区：
文献类型：
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作者：
R. Chini;V. Hoffmeister;A. Nasseri;O. Stahl;H. Zinnecker
大约20 M⊙以上恒星的形成及其明显的高多重性仍然是天体物理学中备受争议的主题。我们对银河系南部的大约250颗O型和540颗B型恒星进行了大量的高分辨率径向速度光谱测量，结果表明，大多数质量在16 M <$m以上的恒星（> 82%）形成了密近双星系统，而对于3 M <$m的恒星，这一比例迅速下降到20%。O型星在不同环境类别中的双星比例为：星团（72 ± 13%）、星协（73 ± 8%）、场（43 ± 13%）和逃逸星（69 ± 11%）。相似质量的组件的密切对的高频率主张赞成起源于形成过程，而不是从一个密集的集群潮汐捕获的多样性。我们在调查中发现的逃逸O型星的双星频率很高（69%，而以前的调查为19- 26%），这表明年轻星星团弹射的重要性，因此支持竞争性吸积的情况。
The formation of stars above about 20 M⊙ and their apparently high multiplicity remain heavily debated subjects in astrophysics. We have performed a vast high-resolution radial velocity spectroscopic survey of about 250 O- and 540 B-type stars in the southern Milky Way which indicates that the majority of stars (>82 per cent) with masses above 16 M⊙ form close binary systems while this fraction rapidly drops to 20 per cent for stars of 3 M⊙. The binary fractions of O-type stars among different environment classes are: clusters (72 ± 13 per cent), associations (73 ± 8 per cent), field (43 ± 13 per cent) and runaways (69 ± 11 per cent). The high frequency of close pairs with components of similar mass argues in favour of a multiplicity originating from the formation process rather than from a tidal capture in a dense cluster. The high binary frequency of runaway O stars that we found in our survey (69 per cent compared to 19–26 per cent in previous surveys) points to the importance of ejection from young star clusters and thus supports the competitive accretion scenario.