标题： 化学与动力学在太阳邻域：对恒星种群和银河系演化的意义 显示英文标题

标题： Chemistry and Kinematics in the Solar Neighborhood: Implications for Stellar Populations and for Galaxy Evolution

摘要： 太阳邻域应该是本地银河系的一个合理样本。 然而，非常接近太阳的长寿盘星的化学丰度分布包含五到十倍于现代更大尺度银河结构星数模型所一致的金属贫乏恒星，$-1 \simlt {\rm [Fe/H]} \simlt -0.4$dex。 完整长寿恒星样本的金属丰度分布长期以来被认为是对银河系早期化学演化阶段的独特约束，因此希望解决这一异常现象。 我们基于第三份格利泽星表与Olsen（1983）的斯特龙格林光度数据，提出了本地G型矮星金属丰度分布的新推导。 这些恒星的运动学数据，以及Edvardsson{\sl 等}（1993）研究的高精度样本的数据，提供了明确的证据，表明[Fe/H]$\sim -0.4$以下的丰度分布包含两个重叠的分布，即厚盘和薄盘。 通过将本地金属丰度分布与最近确定的（Gilmore, Wyse & Jones 1995）太阳附近约1500pc的F/G型恒星{\sl 现场}的金属丰度分布进行比较，我们实现了每个星族相对数量的可靠分解。 银河势场的引力筛分作用对这个第二样本起作用，以分离低速度弥散的薄盘成分，使本地样本中主要留下第二个、速度弥散较高的成分。 这两个数据集的结合使我们能够确定本地悖论的来源：存在一个显著的薄盘（按运动学定义）金属丰度分布尾部，其延伸至${\rm [Fe/H] \approx -0.4}$dex 以下。 这是一个稳健的结论，与星数总和、恒星空间分布等一致。 显示英文摘要

摘要： The immediate Solar neighborhood should be a fair sample of the local Galaxy. However, the chemical abundance distribution of long-lived disk stars very near the Sun contains a factor of five to ten more metal-poor stars, $-1 \simlt {\rm [Fe/H]} \simlt -0.4$ dex, than is consistent with modern star-count models of larger scale Galactic structure. The metallicity distribution of complete samples of long-lived stars has long been recognised as providing unique constraints on the early stages of chemical evolution of the Galaxy, so that one would like to resolve this anomaly. We present a new derivation of the local G-dwarf metallicity distribution, based on the Third Gliese catalog combined with Olsen's (1983) Str\"omgren photometry. Kinematic data for these same stars, as well as for a high-precision sample studied by Edvardsson {\sl et al.} (1993), provide clear evidence that the abundance distribution below [Fe/H]$\sim -0.4$ contains two over-lapping distributions, the thick disk and the thin disk. We achieve a reliable deconvolution of the relative numbers in each population by comparing the local metallicity distribution with a recent determination (Gilmore, Wyse \& Jones 1995) of the metallicity distribution of F/G stars {\sl in situ} some 1500pc from the Sun. The gravitational sieve of the Galactic potential acts on this second sample to segregate the low velocity dispersion, thin-disk, component of the local sample, leaving predominantly the second, higher velocity dispersion component. The combination of these two datasets allows us to determine the source of the local paradox: there is a substantial tail of the thin disk (defined kinematically) metallicity distribution, which extends below ${\rm [Fe/H] \approx -0.4}$dex. This is a robust conclusion, being consistent with the sum of star count, stellar spatial