论文标题
增强双关二二四元
Enhancement of Double-Close-Binary Quadruples
论文作者
论文摘要
双关二二四元素（2+2个系统）是四星级的分层系统，其中两个短周期二进制系统在更宽的轨道上围绕其共同的质量中心移动。使用Gaia Early Data Release 3，我们搜索两个组件都黯然失色的二进制组合对。我们介绍八个2+2个四重系统，内部轨道周期为$ <$ 0.4天，外部分离为$ \ gtrsim 1000 $ au。除一个系统外，所有系统都是由这项工作新发现的，我们从光曲线测量的轨道信息分类。我们发现，2+2个四元素的出现率为7.3 $ \ pm $ 2.6倍，比野外恒星的随机配对的预期高2.6倍。最多可以通过$ \ sim 2 $ 2的增强来解释，这是通过现场恒星人口黯然失色的二元分数的年龄和金属性依赖性。 $ \ sim $ 3的剩余因素代表了大分分开（$> 10^3 $ au）对的短期二进制组的真正增强，这表明可能会通过广泛的同伴来增强近距离的二进制构造通道。
Double-close-binary quadruples (2+2 systems) are hierarchical systems of four stars where two short-period binary systems move around their common center of mass on a wider orbit. Using Gaia Early Data Release 3, we search for comoving pairs where both components are eclipsing binaries. We present eight 2+2 quadruple systems with inner orbital periods of $<$ 0.4 days and with outer separations of $\gtrsim 1000$ AU. All but one system are newly discovered by this work, and we catalog their orbital information measured from their light curves. We find that the occurrence rate of 2+2 quadruples is 7.3 $\pm$ 2.6 times higher than what is expected from random pairings of field stars. At most a factor of $\sim$2 enhancement may be explained by the age and metallicity dependence of the eclipsing binary fraction in the field stellar population. The remaining factor of $\sim$3 represents a genuine enhancement of the production of short-period binaries in wide-separation ($>10^3$ AU) pairs, suggesting a close binary formation channel that may be enhanced by the presence of wide companions.
