Spectroscopic determinations of rubidium abundances were made by applying the spectrum‐fitting method to the Rb(i) 7800 line for an extensive sample of ∼500 late‐type dwarfs as well as giants (including Hyades cluster stars) belonging to the galactic disk population, with the aim of establishing the behavior of [Rb/Fe] ratio for disk stars in the metallicity range of −0.6 ≲ [Fe/H] ≲ +0.3. An inspection of the resulting Rb abundances for Hyades dwarfs revealed that they show a systematic T_eff‐dependent trend at ≳ 5,500 K; this means that the results for mid‐G to F stars (including the Sun) are not reliable (i.e., more or less overestimated), which might be due to some imperfect treatment of surface convection in classical model atmospheres. As such, it was decided to confine only to late‐G and K stars at T_eff ≲ 5,500 K and adopt the solar‐system (meteoritic) value as the reference Rb abundance. The [Rb/Fe] versus [Fe/H] relations derived for field dwarfs and giants turned out to be consistent with each other, showing a gradual increase of [Rb/Fe] with a decrease in [Fe/H] (with d[Rb/Fe]/d[Fe/H] gradient of ∼ −0.4 around the solar metallicity), which compares favorably with the theoretical prediction of chemical evolution models. Accordingly, this study could not confirm the anomalous behavior of [Rb/Fe] ratio (tending to be subsolar but steeply increasing towards supersolar metallicity) recently reported for M dwarf stars of −0.3 ≲ [Fe/H] ≲ +0.3.

中文翻译：

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银盘星的丰度

通过对Rb（i） 7800谱线应用光谱拟合方法对for500晚期型矮星以及银河系星盘种群的巨人（包括海德斯星团恒星）进行广泛的光谱测定，对und的丰度进行了光谱测定。目的是确定盘星在金属度为-0.6≲ [Fe / H] ≲+ 0.3时[Rb / Fe]比的行为。对所得的Hyades矮人的Rb丰度进行检查后发现，它们显示出系统的T _eff依赖性趋势（at5,500）K; 这意味着，中G至F星（包括太阳）的结果不可靠（即或多或少被高估了），这可能是由于在经典模式大气中对表面对流处理不完善所致。因此，它决定只有禁锢晚-G和K星星Ť _EFF  ≲5500 K和采用太阳能系统（陨石）值作为参考RB丰度。结果表明，野外矮人和巨人的[Rb / Fe]与[Fe / H]关系相互一致，显示[Rb / Fe]随着[Fe / H]的降低而逐渐增加（随着d [Rb / Fe] / d [Fe / H]梯度约为-0.4周围的太阳金属度），这与化学演化模型的理论预测相比具有优势。因此，这项研究无法证实最近报道的M矮星-0.3≲ [Fe / H] ≲+ 0.3的[Rb / Fe]比的异常行为（趋于亚太阳，但朝着超太阳金属性急剧增加）。