论文标题
神秘的球状簇UK 〜1被凸起遮挡：\ textit {h} - 频带发现氮增强星星
The enigmatic globular cluster UKS~1 obscured by the bulge: \textit{H}-band discovery of nitrogen-enhanced stars
论文作者
论文摘要
球状簇中富含氮的恒星的存在为多个恒星种群（MPS）提供了关键证据，这已经证明了朝向凸起，磁盘和光晕的球形簇光谱数据证明。在这项工作中，我们采用了VVV红外星体目录（VIVAC）和Apogee调查的DR16 SDSS-IV释放，提供了对凸起的球状群集UKS的首次详细光谱研究。基于这些数据，研究了六个选定的群集成员的样本。我们发现UKS〜1的平均金属性是[Fe/H] $ = -0.98 \ pm0.11 $，比以前报道的金属罚款要多得多，并且金属散射可忽略不计，这是Apogee在其他银河系中观察到的典型的金属散射。此外，我们发现平均径向速度为$ 66.1 \ pm12.9 $ km s $^{ - 1} $，在1 $σ$之内与文献值非常吻合。通过将VIRAC目录中的恒星选择为UKS〜1，我们还测量了（$μ_α\ cos（δ）$，$μ_δ$）$ = $ = $（$ -2.77 \ pm0.23 $，$ -2.43 \ 2.43 \ pm0.16 $）MAS YR $^{ - 1} $。我们发现有力的证据证明了MP在UKS 〜1中的存在，因为这项工作中分析的六个巨人中有四个在氮（[N/Fe] $ \ GTRSIM+0.95 $）方面具有很强的富集，并伴有较低的碳含量（[C/FE] $ \ $ \ sieldsim-sim-0.2 $）。总体而言，光 - （c，n），$α$ - （o，mg，si，ca，ti），fe-peak（fe，ni），odd-z（al，k）和\ textit {s} -process -process（ce，ce，nd，yb）的成员候选人的基本丰度与我们的成员候选人的元素丰富性相似，在全球群体中相似，在全球群体中相似。此外，在其他全局簇（GC）中，典型的元素元素的总体恒星丰度散射是典型的，并且大于某些[x/fe]丰度的典型错误。 VVV颜色磁性图中的统计等异隆的结果表明年龄...
The presence of nitrogen-enriched stars in globular clusters provides key evidence for multiple stellar populations (MPs), as has been demonstrated with globular cluster spectroscopic data towards the bulge, disk, and halo. In this work, we employ the VVV Infrared Astrometric Catalogue (VIRAC) and the DR16 SDSS-IV release of the APOGEE survey to provide the first detailed spectroscopic study of the bulge globular cluster UKS~1. Based on these data, a sample of six selected cluster members was studied. We find the mean metallicity of UKS~1 to be [Fe/H]$=-0.98\pm0.11$, considerably more metal-poor than previously reported, and a negligible metallicity scatter, typical of that observed by APOGEE in other Galactic globular clusters. In addition, we find a mean radial velocity of $66.1\pm12.9$ km s$^{-1}$, which is in good agreement with literature values, within 1$σ$. By selecting stars in the VIRAC catalogue towards UKS~1, we also measure a mean proper motion of ($μ_α\cos(δ)$, $μ_δ$) $=$ ($-2.77\pm0.23$,$-2.43\pm0.16$) mas yr$^{-1}$. We find strong evidence for the presence of MPs in UKS~1, since four out of the six giants analysed in this work have strong enrichment in nitrogen ([N/Fe]$\gtrsim+0.95$) accompanied by lower carbon abundances ([C/Fe]$\lesssim-0.2$). Overall, the light- (C, N), $α$- (O, Mg, Si, Ca, Ti), Fe-peak (Fe, Ni), Odd-Z (Al, K), and the \textit{s}-process (Ce, Nd, Yb) elemental abundances of our member candidates are consistent with those observed in globular clusters at similar metallicity. Furthermore, the overall star-to-star abundance scatter of elements exhibiting the multiple-population phenomenon in UKS~1 is typical of that found in other global clusters (GCs), and larger than the typical errors of some [X/Fe] abundances. Results from statistical isochrone fits in the VVV colour-magnitude diagrams indicate an age ...
