论文标题
银河系磁盘中巨人和矮星的钾丰度的测定
Determination of Potassium Abundances for Giant and Dwarf Stars in the Galactic Disk
论文作者
论文摘要
通过将非LTE光谱分析分析应用于7698.96A的K I共振线，对160个FGK矮人的大量样本和328个G /早期-K巨人（包括89个属于校园的巨人）（包括89个巨人）的Seismolighationalliant agiant（包括89个巨人），从而，对晚期型恒星的钾丰度进行了广泛的研究，以ki i的160 fgk矮人和328个fgk矮人（包括328个fgk矮人）的样本（包括埃普尔（Sepler）的89个巨人（包括89个巨人）） [fe/h] <0.5），这可能对银河磁盘中K的核合成史提供重要的观察性约束。特别注意以[fe/h]以及恒星年龄的形式阐明[k/fe]的观察到的行为，并检查巨人和矮人是否会彼此产生一致的结果。获得以下结果。 （1）[k/fe]的趋势略有增加，[fe/h]（d [k/fe]/d [fe/h]〜 -0.1至-0.15;比以前的研究所报道的较浅的坡度）在FGK dwarfs中得到了证实，尽管厚恒星往往显示出较大的[K/Fe]偏离此渐变。 （2）对于位于太阳邻居（例如矮人）中的明显明显的田野巨头也观察到了几乎相似的特征。 （3）然而，对于更遥远的{\ it kepler}巨人的[k/fe]与[fe/h]的关系显示出更大的散射，并且系统地比矮人更高（<〜0.1dex），这意味着k的化学演变取决于Galaxy的位置。 （4）关于年龄依赖性，矮人认识到[K/Fe随着年龄的增长]的边际趋势，而Kepler巨人却没有观察到任何系统的趋势。这些后果可能表明，在银河磁盘中的时间的演变确实存在，但比以前想象的要逐渐逐渐进行，并且其状况明显依赖于位置。
An extensive study on the potassium abundances of late-type stars was carried out by applying the non-LTE spectrum-fitting analysis to the K I resonance line at 7698.96A to a large sample of 160 FGK dwarfs and 328 late-G /early-K giants (including 89 giants in the Kepler field with seismologically known ages) belonging to the disk population (-1 < [Fe/H] < 0.5), which may provide important observational constraint on the nucleosynthesis history of K in the galactic disk. Special attention was paid to clarifying the observed behaviors of [K/Fe] in terms of [Fe/H] along with stellar age, and to checking whether giants and dwarfs yield consistent results with each other. The following results were obtained. (1) A slightly increasing tendency of [K/Fe] with a decrease in [Fe/H] (d[K/Fe]/d[Fe/H] ~ -0.1 to -0.15; a shallower slope than reported by previous studies) was confirmed for FGK dwarfs, though thick-disk stars tend to show larger [K/Fe] deviating from this gradient. (2) Almost similar characteristics was observed also for apparently bright field giants locating in the solar neighborhood (such as like dwarfs). (3) However, the [K/Fe] vs. [Fe/H] relation for more distant {\it Kepler} giants shows larger scatter and is systematically higher (by <~0.1dex) than that of dwarfs, implying that chemical evolution of K is rather diversified depending on the position in the Galaxy. (4) Regarding the age-dependence, a marginal trend of increasing [K/Fe] with age is recognized for dwarfs, while any systematic tendency is not observed for Kepler giants. These consequences may suggest that evolution of [K/Fe] with time in the galactic disk does exist but proceeded more gradually than previously thought, and its condition is appreciably location-dependent.
