The chemical composition of the low-mass Galactic globular cluster NGC 6362
The chemical composition of the low-mass Galactic globular cluster NGC 6362
复制标题
DOI：
10.1093/mnras/stx549
复制
发表时间：
2017-03
影响因子：
4.8
通讯作者：
D. Massari;D. Massari;A. Mucciarelli;E. Dalessandro;M. Bellazzini;S. Cassisi;Giuliana Fiorentino;R. Ibata;C. Lardo;M. Salaris
中科院分区：
文献类型：
--
作者：
D. Massari;D. Massari;A. Mucciarelli;E. Dalessandro;M. Bellazzini;S. Cassisi;Giuliana Fiorentino;R. Ibata;C. Lardo;M. Salaris
利用UVES光谱测量了NGC 6362中11颗红巨星分支星的17种元素的化学丰度。NGC 6362是目前发现的质量最小的球状星团之一，但其详细的化学成分尚未被研究。NGC 6362是一个中间金属（[Fe/H]=-1.07\pm0.01 dex）团簇，其α和Fe峰元素含量与具有类似金属丰度的团簇一致.它还显示出其s过程元素丰度的增强。在涉及多重居群现象的轻元素中，只有[Na/Fe]显示出星与星星之间的变化，而[Al/Fe]和[Mg/Fe]没有显示出任何丰度分布的证据。与M4（一个具有相似质量和金属丰度的球状星团）的差异比较显示，这两个星团具有相同的化学成分。这一发现表明NGC 6362确实是一个规则的星系团，由经历了与其他具有类似金属丰度的星系团相同的化学富集的气体形成。
We present chemical abundances for 17 elements in a sample of 11 red giant branch stars in NGC 6362 from UVES spectra. NGC 6362 is one of the least massive globulars where multiple populations have been detected, yet its detailed chemical composition has not been investigated so far. NGC 6362 turns out to be a metal-intermediate ([Fe/H]=-1.07\pm0.01 dex) cluster, with its \alpha- and Fe-peak elements content compatible with that observed in clusters with similar metallicity. It also displays an enhancement in its s-process element abundances. Among the light elements involved in the multiple populations phenomenon, only [Na/Fe] shows star-to-star variations, while [Al/Fe] and [Mg/Fe] do not show any evidence for abundance spreads. A differential comparison with M4, a globular cluster with similar mass and metallicity, reveals that the two clusters share the same chemical composition. This finding suggests that NGC 6362 is indeed a regular cluster, formed from gas that has experienced the same chemical enrichment of other clusters with similar metallicity.