Solar Chemical Abundances Determined with a CO5BOLD 3D Model Atmosphere
Solar Chemical Abundances Determined with a CO5BOLD 3D Model Atmosphere
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DOI：
10.1007/s11207-010-9541-4
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发表时间：
2011-02-01
期刊：
影响因子：
2.8
通讯作者：
Bonifacio, P.
中科院分区：
文献类型：
--
作者：
Caffau, E.;Ludwig, H. -G.;Bonifacio, P.
在过去的十年中，光球太阳金属丰度从光谱测定经历了显着的向下修正。这种影响的一部分可以归因于原子数据的改进和NLTE计算的纳入，但流体动力学模型大气的使用似乎也发挥了作用。太阳光球层金属丰度随时间的“减少”增加了与日震学结果的不一致。巴黎天文台的CIFIST小组利用太阳大气CO（5）BOLD三维模型，重新确定了几种元素的光球太阳丰度，其中包括C、N和O。光谱丰度是通过将观测到的谱线的等效宽度和/或轮廓与从3D模型大气计算的合成光谱拟合而获得的。我们的结论是，颗粒涨落的影响依赖于个别线的特性，但被发现是相关的，只有在少数特定的情况下。3D效应并不是近年来太阳丰度系统性下降的原因。太阳的金属丰度Z = 0.0153，Z/X = 0.0209。
In the last decade, the photospheric solar metallicity as determined from spectroscopy experienced a remarkable downward revision. Part of this effect can be attributed to an improvement of atomic data and the inclusion of NLTE computations, but also the use of hydrodynamical model atmospheres seemed to play a role. This "decrease" with time of the metallicity of the solar photosphere increased the disagreement with the results from helioseismology. With a CO(5)BOLD 3D model of the solar atmosphere, the CIFIST team at the Paris Observatory re-determined the photospheric solar abundances of several elements, among them C, N, and O. The spectroscopic abundances are obtained by fitting the equivalent width and/or the profile of observed spectral lines with synthetic spectra computed from the 3D model atmosphere. We conclude that the effects of granular fluctuations de-pend on the characteristics of the individual lines, but are found to be relevant only in a few particular cases. 3D effects are not responsible for the systematic lowering of the solar abundances in recent years. The solar metallicity resulting from this analysis is Z = 0.0153, Z/X = 0.0209.