Galactic chemical evolution of the solar neighborhood, solar twins and exoplanet indicators

Galactic chemical evolution (GCE), solar analogues or twins, and peculiarities of<br> the solar composition with respect to the twins are inextricably related.<br> We examine GCE parameters from the literature and present newly derived values<br> using a quadratic fit that gives zero for a Solar age (i.e. 4.6 Gyr). <br> We show how the GCE parameters may be used not only to ``correct'' abundances<br> to the solar age, but to predict {\bf average} relative elemental <br> abundances as a function of age. <br> We address the question of whether the solar abundances<br> are depleted in refractories and enhanced in volatiles and<br> find that the answer is sensitive to the selection of a<br> representative standard. Our best quality data sets do<br> not support the notion that the Sun is depleted in refractories. <br> A simple model allows us to estimate<br> the amount of refractory-rich material missing from the sun<br> or alternately added to the average solar twin. The model<br> gives between zero and 1.4 earth masses. <br>银河系化学演化（Galactic Chemical Evolution, GCE）、太阳类似星与太阳孪生星，以及太阳成分相较于孪生星的独特特征三者之间存在密不可分的关联。本研究梳理了文献中已有的银河系化学演化参数，并采用针对太阳年龄（即46亿年，Gyr）取值为零的二次拟合方法，给出了新推导的参数值。我们阐明了银河系化学演化参数的双重用途：不仅可将元素丰度"校正"至太阳年龄，还可用于预测随年龄变化的**平均**相对元素丰度。我们探讨了"太阳丰度是否在难熔元素中亏损、在挥发性元素中富集"这一科学问题，并发现该问题的结论取决于代表性标准的选取。我们的高质量数据集并不支持"太阳在难熔元素中存在亏损"这一观点。借助一个简单模型，我们可以估算出太阳缺失的富难熔物质质量，或是平均太阳孪生星额外添加的富难熔物质质量；该模型给出的质量范围为0至1.4倍地球质量。