论文标题
球状簇NGC 6388的原位起源来自大量恒星样本的SC，V和Zn
The in situ origin of the globular cluster NGC 6388 from abundances of Sc, V, and Zn of a large sample of stars
论文作者
论文摘要
球状簇（GC）的化学标记通常使用大量α元素进行。提出了铁峰元素SC，V，尤其是Zn作为alpha元素的替代方法，以在金属丰富的政权中标记积聚的GC，在那里，矮人的Galaxy Sagittarius及其GCS显示出与Milky Way相对于Milky Way Stars的这些Heavier物种的特殊性。 NGC 6388中的少数恒星用于提出该GC的积聚起源，与动力学的结果相矛盾。我们通过在NGC 6388中使用大量恒星样本来测试铁峰方法的效率，而碟片中的数千名田间恒星和银河系的凸起。 NGC 6388的SC（185颗星）和V（35颗星）的丰度比（35颗星）在具有类似金属性的田间恒星的平均值中约为1.5 sigma，对于Zn（31颗恒星）来说，它们是完全敏感的元素。此外，化学图与GC在银河系中GC的分叉年龄关系结合，显然排除了NGC 6388与积聚GC组的任何关联。使用文献中的大量GC丰度，我们还表明，具有SC，V和Zn的新方法似乎有效地拾取了与Sagittarius Dwarf Galaxy相关的GC。对于积聚的GC而言，这是否也是如此，似乎不太明显，应该通过田间和GC中的恒星的较大和均匀样本进行验证。
Chemical tagging of globular clusters (GCs) is often done using abundances of alpha-elements. The iron-peak elements Sc, V, and in particular Zn were proposed as an alternative to alpha-elements to tag accreted GCs in the metal-rich regime, where the dwarf galaxy Sagittarius and its GCs show peculiarly marked under-abundances of these heavier species with respect to Milky Way stars. A handful of stars in NGC 6388 was used to suggest an accreted origin for this GC, contradicting the results from dynamics. We tested the efficiency of the iron-peak method by using large samples of stars in NGC 6388, compared to thousands of field stars in the disc and the bulge of the Milky Way. Our abundance ratios of Sc (185 stars) and V (35 stars) for NGC 6388 are within about 1.5 sigma from the average for the field stars with a similar metallicity, and they are in perfect agreement for Zn (31 stars), claimed to be the most sensitive element concerning the accretion pattern. Moreover, the chemo-dynamical plots, coupled to the bifurcated age-metallicity relation of GCs in the Galaxy, clearly rule out any association of NGC 6388 to the groups of accreted GCs. Using a large set of GC abundances from the literature, we also show that the new method with Sc, V, and Zn seems to be efficient in picking up GCs related to the Sagittarius dwarf galaxy. Whether this is also generally true for accreted GCs seems to be less evident, and it should be verified with larger and homogeneous samples of stars both in the field and in GCs.
