发表机构
Cardiff University; Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences; Max Planck Institute for Astrophysics; University of Nottingham（卡迪夫大学; 波兰科学院尼古拉·哥白尼天文中心; 马克斯·普朗克天体物理研究所; 诺丁汉大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出双黑洞动力学配对的有序抽取关系，用星团模拟验证，并应用于引力波种群，解释次级质量分布下降，为形成通道提供诊断。
AI 中文摘要
在星团中动力学形成的双黑洞通常与近等质量配对相关联。我们表明这一预期是不完整的。动力学组装的更一般预测是一种有序配对关系，其中两个黑洞独立地从共同的一体质量谱中抽取，然后按质量排序。一旦主质量分布已知，这种关系就确定了条件伴星分布$p(m_2\mid m_1)$。我们用星团模拟验证了这一图景。在这些模型中，有序抽取关系再现了质量配对分布的形态，包括从一体质量谱继承的固定$m_2$脊：在几乎恒定的次级质量处的特征，延伸到一系列主质量范围，因此对应于随着$m_1$增加而减小的$q=m_2/m_1$。因此，质量分布本身的几何形状成为形成通道的诊断工具。动力学配对将主质量谱的峰值映射为具有可预测振幅的固定$m_2$脊，而孤立双星演化更自然地产生固定$q$的结构。将这一测试应用于引力波种群的非参数重建，我们发现$m_1\gtrsim 40~M_\odot$时$m_2\simeq 30~M_\odot$处有初步增强，与有序配对大致兼容。最后，我们表明动力学形成自然地解释了最近LIGO--Virgo--KAGRA合作报告的次级质量分布在$\sim30~M_\odot$以上的快速下降。
英文摘要
Binary black holes formed dynamically in star clusters are often associated with nearly equal-mass pairing. We show that this expectation is incomplete. The more general prediction of dynamical assembly is an ordered-pairing relation in which the two black holes are drawn independently from a common one--body mass spectrum and then ordered by mass. Once the primary-mass distribution is known, this relation fixes the conditional companion distribution $p(m_2\mid m_1)$. We validate this picture with cluster simulations. In these models, the ordered-draw relation reproduces the morphology of the mass-pairing distribution, including fixed-$m_2$ ridges that are inherited from the one--body mass spectrum: features at nearly constant secondary mass that extend over a range of primary masses and therefore correspond to decreasing $q=m_2/m_1$ as $m_1$ increases. Thus, the geometry of the mass distribution itself becomes a formation-channel diagnostic. Dynamical pairing maps peaks of the primary-mass spectrum into fixed-$m_2$ ridges with predictable amplitude, whereas isolated binary evolution more naturally produces structures at fixed $q$. Applying this test to a non-parametric reconstruction of the gravitational-wave population, we find a tentative enhancement at $m_2\simeq 30~ M_\odot$ for $m_1\gtrsim 40~ M_\odot$ that is broadly compatible with ordered pairing. Finally, we show that dynamical formation naturally explains the rapid decline of the secondary-mass distribution above $\sim30~M_\odot$ recently reported by the LIGO--Virgo--KAGRA Collaboration.
Comments20 pages, 11 figures. Comments are welcomed
