发表机构
School of Physics and Technology, Wuhan University; School of Physics and Astronomy, Beijing Normal University; Max Planck Institute for Gravitational Physics (Albert Einstein Institute); Zhejiang Key Laboratory of Extreme Universe, Ningbo University; Institute of Fundamental Physics and Quantum Technology, Ningbo University（武汉大学物理科学与技术学院; 北京师范大学物理与天文学院; 马克斯·普朗克引力物理研究所（爱因斯坦研究所）; 宁波大学极端宇宙浙江省重点实验室; 宁波大学基础物理与量子技术研究院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过TEOBResumS-Dalí模型分析GW231123数据，测得其5.5 Hz处偏心率为0.34，贝叶斯因子10.2支持偏心模型，表明该事件是致密环境中双黑洞层级并合的产物。
AI 中文摘要
GW231123是迄今为止观测到的质量最大的双黑洞并合事件，也是对对不稳定质量间隙中最具吸引力的层级并合候选体之一。其推断的组分自旋异常大，且带内持续时间极短，使得该源对并合附近的波形物理高度敏感。在此，我们表明GW231123更适合被描述为偏心双黑洞并合事件。我们使用偏心、自旋进动的有效一体波形模型TEOBResumS-Dalí分析11–448 Hz范围内的数据，同时考虑探测器校准不确定性。我们在90%可信度下测得$e_{5.5\textrm{Hz}}=0.34^{+0.12}_{-0.23}$，并获得支持偏心模型而非准圆形模型的贝叶斯因子为10.2。类似GW231123的注入-恢复研究进一步表明，如以往研究那样从20 Hz开始的分析会掩盖这种偏心率。纳入偏心率会显著改变自旋推断，减弱对近极值次级自旋的偏好，并将其后验中位数降至$a_2\backsimeq0.7$，接近黑洞并合残余体的特征自旋。这些结果为GW231123提供了一致的动力学解释，其中残余偏心率、质量间隙黑洞和残余体样自旋均自然产生于致密环境中的层级并合通道。
英文摘要
GW231123 is the most massive binary black hole merger observed to date and one of the most intriguing hierarchical merger candidates in the pair-instability mass gap. Its exceptionally large inferred component spins and remarkably short in-band duration make the source highly sensitive to waveform physics near merger. Here we show that GW231123 is better described as an eccentric binary black-hole merger. We analyse data over 11--448 Hz using the eccentric, spin-precessing effective-one-body waveform model TEOBResumS--Dalí, accounting for detector calibration uncertainty. We measure $e_{5.5\,\mathrm{Hz}}=0.34^{+0.12}_{-0.23}$ at 90\% credibility and obtain a Bayes factor of 10.2 in favour of the eccentric model over its quasi-circular counterpart. GW231123-like injection--recovery studies further show that analyses starting at 20 Hz, as in previous studies, can obscure this eccentricity. Including eccentricity substantially changes the spin inference, weakening the preference for a near-extremal secondary spin and lowering its posterior median to $a_2\simeq0.7$, close to the characteristic spin expected for a black-hole merger remnant. These results provide a coherent dynamical interpretation of GW231123, in which residual eccentricity, a mass-gap black hole, and a remnant-like spin arise naturally from a hierarchical merger channel in a dense environment.
Comments12 pages, 7 figures, comments welcome
