发表机构
The University of Texas at Austin; California Institute of Technology; LIGO Laboratory; Rochester Institute of Technology（德克萨斯大学奥斯汀分校; 加州理工学院; LIGO实验室; 罗切斯特理工学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对GW190521高总质量导致解释简并的问题，利用多族波形模型重新分析，发现源高偏心（0.81），并揭示偏心-自旋进动简并性，确认主黑洞位于质量间隙，贡献在于厘清波形系统误差来源。
AI 中文摘要
由于GW190521的总质量异常高，可观测的引力波周期数相应较少，这导致不同物理解释之间存在简并性，因此对其解释仍具挑战性。受该事件相关未决问题的启发，我们使用来自多个族的波形模型对GW190521进行了全面重新分析，其中包括同时包含偏心率和自旋进动的模型。我们发现证据表明该源具有高偏心率，在5 Hz处推断的偏心率为$0.81^{+0.05}_{-0.01}$，并表明非偏心解释源于未能探测大偏心率下的高似然区域。我们进一步证明，当分析中包含偏心率时，没有自旋进动的迹象，这表明准圆分析中表现出的进动至少部分由偏心-自旋进动简并性驱动。虽然所有波形模型都倾向于质量相近的双星，但一个模型允许在更不对称的质量处存在次级模式。我们发现主黑洞位于对不稳定超新星质量间隙（约$60-130\\,M_\odot$）内的稳健概率（$\geq97\\%$），而次黑洞位于间隙内的概率取决于波形模型。通过对类似GW190521的注入进行推断，我们表明在GW190521分析中观察到的波形系统误差可能源于模型对未建模偏心率的响应，而非波形模型之间的内在差异。当分析类似GW190521的准圆自旋进动注入时，我们发现推断参数没有显著的模型依赖性。最后，由于推断的偏心率超出了当前模型的校准范围，我们通过恢复高偏心数值相对论波形来测试其稳健性。
英文摘要
Interpreting GW190521 remains challenging due to its exceptionally high total mass and correspondingly small number of observable gravitational-wave cycles, which gives rise to degeneracies between different physical interpretations. Motivated by the outstanding questions surrounding the event, we present a comprehensive reanalysis of GW190521 using waveform models drawn from multiple families, including a model that includes both eccentricity and spin-precession. We find evidence that the source was highly eccentric, with an inferred eccentricity of $0.81^{+0.05}_{-0.01}$ at 5 Hz, and show that non-eccentric interpretations arise from failing to probe the high-likelihood region at large eccentricities. We further demonstrate that when eccentricity is included in the analysis, there is no indication of spin precession, suggesting that the apparent precession in quasicircular analyses is at least partially driven by an eccentricity--spin-precession degeneracy. While all waveform models favor a comparable-mass binary, one model admits a secondary mode at more asymmetric masses. We find a robust probability $(\geq97\%)$ that the primary black hole lies within the pair-instability supernova mass gap ($\sim60-130\,M_\odot$), whereas the probability that the secondary lies in the gap depends on the waveform model. Through inference of GW190521-like injections, we show that the waveform systematics observed in the analysis of GW190521 could arise from the response of models to unmodeled eccentricity, rather than from intrinsic differences between waveform models. When analyzing a quasicircular spin-precessing injection similar to GW190521, we find no significant model dependence in the inferred parameters. Finally, because the inferred eccentricity lies beyond the calibration regime of current models, we test its robustness by recovering highly eccentric numerical-relativity waveforms.
Comments16 pages, 7 Figures and 3 Tables
