We explore chemically homogeneous evolution (CHE) as a formation channel for massive merging binary black holes (BBHs). We develop methods to include CHE in a rapid binary population synthesis code, Compact Object Mergers: Population Astrophysics and Statistics (compas), which combines realistic models of binary evolution with cosmological models of the star formation history of the Universe. For the first time, we simultaneously explore conventional isolated binary star evolution under the same set of assumptions. This approach allows us to constrain population properties and make simultaneous predictions about the gravitational-wave detection rates of BBH mergers for the CHE and conventional formation channels. The overall mass distribution of detectable BBHs is consistent with existing gravitational-wave observations. We find that the CHE channel may yield up to ${\sim} 70{{\ \rm per\ cent}}$ of all gravitational-wave detections of BBH mergers coming from isolated binary evolution.

中文翻译：

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化学同质进化：一种快速的种群合成方法

我们探索化学均匀演化 (CHE) 作为大规模合并双黑洞 (BBH) 的形成通道。我们开发了将 CHE 包含在快速二进制种群合成代码中的方法，即紧凑对象合并：种群天体物理学和统计 (compas)，它将二进制演化的现实模型与宇宙恒星形成历史的宇宙模型相结合。我们第一次在同一组假设下同时探索传统的孤立双星演化。这种方法使我们能够约束种群属性并同时预测 CHE 和常规地层通道的 BBH 合并的引力波探测率。可探测 BBH 的总体质量分布与现有的引力波观测结果一致。