论文标题
56个银河凸起红色巨人的钴和铜丰度
Cobalt and copper abundances in 56 Galactic bulge red giants
论文作者
论文摘要
银河系凸起是星系早期形成和化学富集的重要示踪剂。田间凸起恒星中不同铁峰元素的丰度可以提供有关最早的超新星发生的核合成过程的信息。钴（Z = 27）和铜（Z = 29）特别有趣。我们旨在识别负责铁峰元素CO和CU形成的核合成过程。方法。我们在56个凸起的巨人中得出了铁峰元素钴和铜的丰富性，其中13个是红色的恒星。 2000 - 2002年，我们的组使用ESO非常大的望远镜的火焰UVE获得了高分辨率光谱，这似乎是迄今为止在文献中获得的凸起红色巨人的高分辨率高分辨率数据的最高质量样本。多年来，我们得出了C，N，O，Na，Al，Mg的丰富。铁组元素Mn和Zn；和中子捕获元素。在目前的工作中，我们得出了大量的铁峰元素钴和铜。我们还计算化学动力学进化模型，以将这些元素的观察到的行为解释为铁的函数。样品恒星在所有金属率下显示[CO/Fe] 〜0.0的平均值，对于[Fe/H]> -0.8，[Cu/Fe] 〜0.0 〜0.0，并以次级元素的行为降低降低金属率。我们得出的结论是，[co/fe]随[fe/h]的锁定变化，这表明它应在大型恒星中的α富冻结机制中产生。取而代之的是[Cu/Fe]遵循次级元素对较低金属性的行为，表明其在HE燃烧和更后的阶段的弱S过程中产生。这里介绍的化学动力学模型证实了这两个元素的行为（即[co/fe]与[Fe/h]〜常数和[Cu/fe]随着金属率的降低）。
The Milky Way bulge is an important tracer of the early formation and chemical enrichment of the Galaxy. The abundances of different iron-peak elements in field bulge stars can give information on the nucleosynthesis processes that took place in the earliest supernovae. Cobalt (Z=27) and copper (Z=29) are particularly interesting.We aim to identify the nucleosynthesis processes responsible for the formation of the iron-peak elements Co and Cu. Methods. We derived abundances of the iron-peak elements cobalt and copper in 56 bulge giants, 13 of which were red clump stars. High-resolution spectra were obtained using FLAMES-UVES at the ESO Very Large Telescope by our group in 2000-2002, which appears to be the highest quality sample of high-resolution data on bulge red giants obtained in the literature to date. Over the years we have derived the abundances of C, N, O, Na, Al, Mg; the iron-group elements Mn and Zn; and neutron-capture elements. In the present work we derive abundances of the iron-peak elements cobalt and copper. We also compute chemodynamical evolution models to interpret the observed behaviour of these elements as a function of iron. The sample stars show mean values of [Co/Fe]~0.0 at all metallicities, and [Cu/Fe]~0.0 for [Fe/H]>-0.8 and decreasing towards lower metallicities with a behaviour of a secondary element. We conclude that [Co/Fe] varies in lockstep with [Fe/H], which indicates that it should be produced in the alpha-rich freezeout mechanism in massive stars. Instead [Cu/Fe] follows the behaviour of a secondary element towards lower metallicities, indicating its production in the weak s-process nucleosynthesis in He-burning and later stages. The chemodynamical models presented here confirm the behaviour of these two elements (i.e. [Co/Fe] vs. [Fe/H]~constant and [Cu/Fe] decreasing with decreasing metallicities).
