论文标题
关于恒星簇中双峰旋转速度分布的起源：前序列上的旋转
On the Origin of the Bimodal Rotational Velocity Distribution in Stellar Clusters: Rotation on the Pre-Main Sequence
论文作者
论文摘要
我们解决了观察到的恒星和中级恒星群中恒星的双峰旋转分布的起源。这种双峰性被视为年轻年龄段的分裂主要序列，并且最近在巨大的年轻和中级年龄群中的恒星分布中也直接观察到。以前的模型将二进制相互作用作为这种双峰性的起源，尽管这些模型无法重现问题上的所有观察性约束。在这里，我们建议这种双峰旋转分布在集群的生活中，即在前几个MYR内建立。观察结果表明，低质量（$ \ la 2 m_ \ odot $）的周期分布在许多年轻的开放簇中是双峰的，我们提出了一系列型号，以表明，如果这种双态性存在于PMS上的恒星，则预计会表现为固定质量/液体质量/液体的质量/液体质量（在PMS上都具有固定量的质量/液体量） $ \ sim1.5 $〜\ msun。 PMS恒星的这种双峰时期分布可能是由于恒星在整个PMS寿命中是否丢失（快速旋转器）或能够保留（慢旋转器）其间隔盘。我们根据模型对可观察物的一系列预测结束。
We address the origin of the observed bimodal rotational distribution of stars in massive young and intermediate age stellar clusters. This bimodality is seen as split main sequences at young ages and also has been recently directly observed in the $Vsini$ distribution of stars within massive young and intermediate age clusters. Previous models have invoked binary interactions as the origin of this bimodality, although these models are unable to reproduce all of the observational constraints on the problem. Here we suggest that such a bimodal rotational distribution is set up early within a cluster's life, i.e., within the first few Myr. Observations show that the period distribution of low-mass ($\la 2 M_\odot$) pre-main sequence (PMS) stars is bimodal in many young open clusters and we present a series of models to show that if such a bimodality exists for stars on the PMS that it is expected to manifest as a bimodal rotational velocity (at fixed mass/luminosity) on the main sequence for stars with masses in excess of $\sim1.5$~\msun. Such a bimodal period distribution of PMS stars may be caused by whether stars have lost (rapid rotators) or been able to retain (slow rotators) their circumstellar discs throughout their PMS lifetimes. We conclude with a series of predictions for observables based on our model.
