论文标题
开放群集库存中的化学奇特星2
Chemically Peculiar Stars in the Open Cluster Stock 2
论文作者
论文摘要
最近重新发现的开放式群集2位于大约375 pc，大约400 Myr Old，有可能成为我们对Stellar Evolution的理解的令人兴奋的新测试床。我们提出了一场光谱运动的结果，以表征群集的主要序列转口附近的恒星；我们的目标是在集群的A星中确定候选人的化学特殊恒星。我们在美国莫纳·基亚天文台（Mauna Kea Observatory）的3.6米加拿大 - 弗朗西·霍瓦伊（Canada-France-Hawaii）望远镜上获得了64个集群成员的Echelle Spectra，在法国Observatoire de Haute Provence的1.93米望远镜上，索菲（Sophie）在1.93米处与Sophie一起使用6颗星。我们与竖琴档案中的13个高质量群集成员的观察结果相辅相成。我们的总体样本为71颗恒星。我们使用切片的逆回归（SIR）技术得出了样品的基本参数（Teff，Log G，[M/H]）以及Vsini，然后使用ISPEC来得出12种化学物种的单个丰度。通过这些丰度确定，我们确定了九个A恒星，具有异常水平的SC，CA和其他金属线。对这些AM候选者的后续观察可以将它们转化为包括原子扩散在内的进化模型的基准，并有助于更好地理解恒星内部宏观和微观过程之间的复杂相互作用。
The recently re-discovered open cluster Stock 2, located roughly 375 pc away and about 400 Myr old, has the potential to be an exciting new testbed for our understanding of stellar evolution. We present results from a spectroscopic campaign to characterize stars near the cluster's main-sequence turnoff; our goal is to identify candidate chemically peculiar stars among the cluster's A stars. We obtained echelle spectra for 64 cluster members with ESPaDOnS on the 3.6-m Canada-France-Hawaii Telescope, Mauna Kea Observatory, USA, and for six stars with SOPHIE on the 1.93-m telescope at the Observatoire de Haute-Provence, France. We complemented these new observations with those of 13 high-mass cluster members from the HARPS-N archive; our overall sample is of 71 stars. We derived the fundamental parameters (Teff, log g, [M/H]) as well as vsini for our sample using the Sliced Inverse Regression (SIR) technique, and then used iSpec to derive individual abundances of 12 chemical species. With these abundance determinations, we identified nine A stars with anomalous levels of Sc, Ca, and other metallic lines. Follow-up observations of these Am candidates with a known age can transform them into benchmarks for evolutionary models that include atomic diffusion and help build a better understanding of the complex interactions between macroscopic and microscopic processes in stellar interiors.
