标题： 盖亚-ESO调查：船底座星云中B型恒星的投影自转速度 显示英文标题

标题： The Gaia-ESO Survey: Projected Rotational Velocities of B stars in the Carina Nebula

摘要： Carina星云是一个活跃的恒星形成区域，包含多个富含大质量OB星的疏散星团，因此它是研究这些早型恒星的旋转等恒星性质的理想目标。我们研究了Carina复合体中8个疏散星团中可能成员的早型恒星样本。观测数据来自Gaia-ESO公开光谱调查的高分辨率光谱。使用Gaia EDR3的天体测量和测光数据以及从观测光谱中测得的视向速度来确认星团成员。从4388和4471\AA 波长处的\ion{He}{i}线宽度得出Carina中330颗早型恒星的投影旋转速度。报告的\Vsini 值是对222颗早型恒星的首次估计。Carina星团的\Vsini 分布在$\sim$100-150 \kms 处达到峰值，与银河系星团中B星的分布一致。首次在文献中给出了Trumpler 15、Collinder 228、Collinder 232和Bochum 11星团成员恒星的\Vsini 估计值。 对于光谱类型从B0到B3的恒星子样本，我们发现分布呈双峰状，在\Vsini 的较高值方向有一个较小的第三峰。 当根据母簇对整个样本进行划分时，我们发现我们样本中年龄最大的星团NGC 3293表现出更快旋转恒星的更高集中度。 相反，Collinder 228表现出更多具有较低\Vsini 的恒星。 显示英文摘要

摘要： The Carina Nebula is an active star-forming region with several open clusters rich in massive OB stars, thus making it an optimal target for studying stellar properties such as rotation for large samples of these early-type stars. We studied a sample of early-type stars probable members of the 8 open clusters in the Carina Complex. The observational data consist of high-resolution spectra from the Gaia-ESO public Spectroscopic Survey. Astrometric and photometric data from Gaia EDR3 and radial velocities measured from the observed spectra are used to confirm the cluster members. The projected rotational velocities of 330 early-type stars of Carina are derived from the widths of \ion{He}{i} lines at 4388 and 4471 \AA. The reported \Vsini\ values are the first estimates for 222 early-type stars. The \Vsini\ distribution for the Carina clusters peaks at $\sim$100-150 \kms, consistent with the distributions for B stars in Galactic clusters. \Vsini\ estimates for stars members of the clusters Trumpler 15, Collinder 228, Collinder 232, and Bochum 11 are presented for the first time in the literature. For a subsample of stars with earlier spectral types from B0 to B3, we find a bimodal distribution, with a third, small peak towards the upper values of \Vsini. When the full sample is split according to the parent cluster, we find that the oldest cluster in our sample, NGC 3293, presents a higher concentration of rapidly rotating stars. In contrast, Collinder 228 presents a larger number of stars with lower \Vsini.