arXiv 0910.47302009-10-25astro-ph.SR

粒化对贫金属星中性铜共振线的影响

Effects of granulation on neutral copper resonance lines in metal-poor stars

P. Bonifacio, E. Caffau, H. -G. Ludwig

备注：: Poster presented at IAU GA 2009, JD 10, to be published on Memorie della SAIt, Vol. 80 n.3

摘要：

我们利用三维流体动力学模拟的影响，造粒的Cu I线的Mult。1在324.7 nm和327.3 nm处的近紫外区。这些线仍然很强，即使在非常低的金属，并提供了机会，研究化学演变的铜在金属贫人口。我们发现这些线上有很强的颗粒效应。在丰度方面，忽略这种影响可能导致高估的A（铜）高达0.8德克斯在矮星。与贫金属球状星团NGC 6752和NGC 6397中恒星的计算结果比较表明，由Mult得到的铜丰度之间存在系统性差异。2在TO星和那些衍生的巨星在同一集群的线的Mult。2在510.5 nm和587.2 nm处。我们的结论是，铜我共振线是不可靠的指标，铜丰度，我们认为，调查偏离LTE是强制性的，利用这些线路。

英文摘要：

We make use of three dimensional hydrodynamical simulations to investigate the effects of granulation on the Cu I lines of Mult. 1 in the near UV, at 324.7 nm and 327.3 nm. These lines remain strong even at very low metallicity and provide the opportunity to study the chemical evolution of Cu in the metal-poor populations. We find very strong granulation effects on these lines. In terms of abundances the neglect of such effects can lead to an overestimate of the A(Cu) by as much as 0.8 dex in dwarf stars. Comparison of our computations with stars in the metal-poor Globular Clusters NGC 6752 and NGC 6397, show that there is a systematic discrepancy between the copper abundances derived from Mult. 2 in TO stars and those derived in giant stars of the same cluster from the lines of Mult. 2 at at 510.5 nm and 587.2 nm. We conclude that the Cu I resonance lines are not reliable indicators of Cu abundance and we believe that an investigations of departures from LTE is mandatory to make use of these lines.

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摘要：

英文摘要：

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