发表机构
International Center for Theoretical Physics Asia-Pacific, University of Chinese Academy of Sciences; Taiji Laboratory for Gravitational Wave Universe, University of Chinese Academy of Sciences（国际理论物理中心亚太分署，中国科学院大学; 太极引力波宇宙实验室，中国科学院大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究预测恒星级双黑洞多频段引力波探测率与参数精度，发现分赫兹观测主导多数参数改进，协调调度和亚阈值搜索可显著提升科学产出。
AI 中文摘要
恒星级双黑洞在并合前会扫过毫赫兹、分赫兹和千赫兹引力波频段，使其成为多频段观测的首要目标。我们预测了由毫赫兹观测台LISA、Taiji和TianQin，分赫兹概念台LGWA、AMIGO和AMIGO-5，以及地面台LVK和Cosmic Explorer组成的网络对其探测率和参数估计精度。利用从GWTC-4推断出的双黑洞质量与红移分布，我们首先估计单频段产率，然后在计算多频段产率时明确考虑探测器寿命和相对任务启动时间。对于信噪比阈值为8的情况，LISA-Taiji-TianQin网络预计将在毫赫兹频段探测到$53.6^{+19.7}_{-14.1}$个系统，而最大的三频段产率为LISA-Taiji-TianQin与LGWA组合时的$23.5^{+8.7}_{-6.2}$个事件。当分赫兹观测在毫赫兹任务开始后约$0$-$3\,{\ m yr}$开始时，产率最大化。阈值为5的地面信息辅助亚阈值搜索将多频段产率提高约$4$-$5$倍，对同一网络达到$125.1^{+46.1}_{-32.9}$个事件。对类似GW150914源的Fisher矩阵预测表明，分赫兹观测对大多数多频段参数约束提供了主要改进，而毫赫兹数据主要增强了探测器帧啁啾质量和天空定位。将三个频段结合可将啁啾质量精度相对于仅地面观测提高数个数量级，并能大幅减小定位区域和并合时间不确定性。这些结果表明，协调的任务调度和有针对性的亚阈值搜索对于实现恒星级多频段引力波天文学的科学潜力至关重要。
英文摘要
Stellar-mass binary black holes sweep through the millihertz, decihertz, and kilohertz gravitational-wave bands before merger, making them prime targets for multiband observations. We forecast their detection rates and parameter-estimation precision for networks combining the millihertz observatories LISA, Taiji, and TianQin; the decihertz concepts LGWA, AMIGO, and AMIGO-5; and the ground-based LVK and Cosmic Explorer. Using the binary-black-hole mass and redshift distributions inferred from GWTC-4, we first estimate the single-band yields and then account explicitly for detector lifetimes and relative mission start times when calculating multiband rates. For a signal-to-noise-ratio threshold of 8, the LISA--Taiji--TianQin network is expected to detect $53.6^{+19.7}_{-14.1}$ systems in the millihertz band, while the largest three-band yield is $23.5^{+8.7}_{-6.2}$ events for LISA--Taiji--TianQin combined with LGWA. The yield is maximized when the decihertz observation begins approximately $0$--$3\,{\rm yr}$ after the millihertz mission. Ground-informed subthreshold searches with a threshold of 5 increase the multiband yields by a factor of approximately $4$--$5$, reaching $125.1^{+46.1}_{-32.9}$ events for the same network. Fisher-matrix forecasts for a GW150914-like source show that decihertz observations provide the dominant improvement in most multiband parameter constraints, whereas millihertz data primarily sharpen the detector-frame chirp mass and sky localization. Combining the three bands improves the chirp-mass precision by orders of magnitude relative to ground-based observations alone and can reduce the localization area and coalescence-time uncertainty substantially. These results demonstrate that coordinated mission scheduling and targeted subthreshold searches are essential for realizing the scientific potential of stellar-mass multiband gravitational-wave astronomy.
Comments16 pages, 10 figures, 7 tables
