Rotation of Early B-type Stars in the Large Magellanic Cloud: the role of Evolution and Metallicity
Rotation of Early B-type Stars in the Large Magellanic Cloud: the role of Evolution and Metallicity
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大麦哲伦星云中早期 B 型恒星的旋转：演化和金属丰度的作用
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发表时间：
2004
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通讯作者：
S. Keller
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文献类型：
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作者：
S. Keller
我目前的测量投影旋转速度的样本100早期B型主序星在大麦哲伦星云（LMC）。这是第一次对恒星自转速度分布的河外研究。样本来自两个来源：来自年轻星团（年龄1-3 × 107年）的主序转折点附近和一般区域。我发现，集群人口表现出显着更快的旋转比在现场看到的。我从文献中提取了类似的银河系星团和磁场样本。这些样品的比较揭示了相同的效果。我建议，观察到的集群和现场人口之间的差异可以解释的情况下，进化增强的表面角动量的主序星寿命。为了探索金属丰度的影响，我们对大麦哲伦星系和银河系的星系团和场的总体进行了比较。这表明大麦哲伦星系的恒星比银河系的恒星旋转得更快。
I present measurements of the projected rotational velocities of a sample of 100 early B-type main-sequence stars in the Large Magellanic Cloud (LMC). This is the first extragalactic study of the distribution of stellar rotational velocities. The sample is drawn from two sources: from the vicinity of the main-sequence turnoff of young clusters (ages 1–3 × 107 yr) and from the general field. I find that the cluster population exhibits significantly more rapid rotation than that seen in the field. I have drawn analogous Galactic cluster and field samples from the literature. Comparison of these samples reveals the same effect. I propose that the observed difference between cluster and field populations can be explained by a scenario of evolutionary enhancement of the surface angular momentum over the main-sequence lifetime. A comparison is made between the cluster and field populations of the LMC and the Galaxy in order to explore the effects of metallicity. This shows that the stars of the LMC are more rapid rotators than their Galactic counterparts.