发表机构
Harvard Society of Fellows; Center for Astrophysics | Harvard & Smithsonian; Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA); Department of Physics and Astronomy, Northwestern University; Département d’Astronomie, Université de Genève; Gravitational Wave Science Center (GWSC), Université de Genève; The Adler Planetarium（哈佛学会; 天体物理中心 | 哈佛与史密森尼学会; 天体物理学跨学科探索与研究中心; 西北大学物理与天文系; 日内瓦大学天文学系; 日内瓦大学引力波科学中心; 阿德勒天文馆）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究人员利用POSYDON代码，发现孤立双星演化产生的双黑洞质量比分布，与引力波观测到的低质量双黑洞子群分布一致，该分布的特征源于不同的形成子通道。
AI 中文摘要
观测到的并合双黑洞群越来越符合由不同子群混合组成，每个子群可能对应不同的形成机制。特别是初级黑洞质量约低于15倍太阳质量的低质量子群，被认为源于孤立双星演化形成的并合。我们使用双星种群合成代码POSYDON，研究孤立双星演化产生的双黑洞并合的质量比（q）分布，并与观测到的低质量子群进行对比。我们探索了超新星遗迹方案、公共包层效率和黑洞吸积效率的变化情况。研究发现，我们的模型倾向于不对称的质量比，多数模型的质量比在q约为0.5-0.7处有一个宽峰，同时存在近相等质量的成分，该成分的相对强度随模型不同而变化。这一得到的质量比分布与引力波观测到的低质量子群的质量比分布一致。我们发现，对于大多数模型，这些特征源于物理上不同的形成子通道：不对称峰反映了来自公共包层和稳定质量转移系统的贡献，而近相等质量成分则对应双核心公共包层和相接系统。我们得出结论，观测到的低质量子群质量比分布的特征，在一系列模型假设下，是孤立双星演化的自然结果。随着引力波星表不断扩充，这些质量比特征的相对强度将为孤立双星演化及其形成子通道提供越来越有力的诊断手段。
英文摘要
The observed merging binary black hole population is increasingly consistent with being composed of a mixture of subpopulations, each likely the result of different formation mechanisms. In particular, the low-mass subpopulation, with primary black hole masses below $\approxeq 15\,M_{\odot}$, has been attributed to mergers formed through isolated binary evolution. We use the binary population synthesis code POSYDON to study the mass ratio $(q)$ distribution of binary black hole mergers from isolated binary evolution and compare to the observed low-mass subpopulation. We explore variations in supernova remnant prescriptions, common-envelope efficiency, and black hole accretion efficiency. We find that our models have a preference for asymmetric $q$, most with a broad peak near $q\approxeq0.5-0.7$, and a near-equal-mass component whose relative strength varies across models. This resultant $q$ distribution is consistent with the $q$ distribution of the low-mass subpopulation observed with gravitational waves. We find that for the majority of models these features arise from physically distinct formation subchannels: the asymmetric peak reflects contributions from common-envelope and stable mass-transfer systems, while the near-equal-mass component traces double-core common envelope and contact systems. We conclude that the features in the $q$ distribution of the observed low-mass subpopulation emerge naturally from isolated binary evolution across a range of model assumptions. As the gravitational-wave catalog continues to grow, the relative strength of these $q$ features will provide an increasingly powerful diagnostic of isolated binary evolution and its formation subchannels.
Comments14 pages, 3 figures
