论文标题
并不是那么简单：宽二元分数随着分离和恒星质量的变化的金属性依赖性变化
Not that simple: the metallicity dependence of the wide binary fraction changes with separation and stellar mass
论文作者
论文摘要
宽二元分数（WBF）的金属性依赖性对于研究宽二进制的形成至关重要。近年来发现有争议的结果。在这里，我们结合了Gaia EDR3认可的宽二进制目录和Lamost的恒星参数来研究该主题。考虑到给定分离的恒星温度的偏差，我们发现WBF和金属性之间的关系取决于S> 200 AU处的薄盘的温度。随着温度从4000 k升高到7500 k，它从阴性变为正变为正变化。对于厚盘而言，这种温度/质量依赖性未见。此外，WBF和金属性之间的一般趋势与分离有所不同，与先前的结果一致。它显示在小分离处的抗相关性，用于薄盘的s <200 au，厚度<600 au用于厚盘。然后，它在较大的分离（数百到数千个AU）上变成了“弧形”形状，对于厚磁盘，峰值达到[Fe/H] 〜0.1的峰值，对于厚磁盘，[Fe/H]〜 -0.5峰值。最后，对于1000 <s <10000 au的薄盘而变得大致平坦。我们的工作为二元形成和进化的理论研究提供了新的观察证据。
The metallicity dependence of the wide binary fraction (WBF) is critical for studying the formation of wide binaries. While controversial results have been found in recent years. Here we combine the wide binary catalog recognized from Gaia EDR3 and stellar parameters from LAMOST to investigate this topic. Taking bias of the stellar temperature at given separations into account, we find that the relationship between the WBF and metallicity depends on temperature for the thin-disk at s > 200 AU. It changes from negative to positive as the temperature increases from 4000 K to 7500 K. This temperature/mass dependence is not seen for the thick-disk. Besides, the general tendency between the WBF and metallicity varies with the separation, consistent with previous results. It shows anti-correlation at small separations, s < 200 AU for the thin-disk and s < 600 AU for the thick-disk. Then it becomes an "arcuate" shape at larger separations (hundreds to thousands of AU), peaking at [Fe/H] ~ 0.1 for the thin-disk and [Fe/H] ~ -0.5 for the thick disk. Finally it becomes roughly flat for the thin-disk at 1000 < s < 10000 AU. Our work provides new observational evidences for theoretical studies on binary formation and evolution.
