利用下一代引力波天文台对第三星族遗迹的表征前景
Prospects for characterizing Population III remnants with next-generation gravitational-wave observatories
浏览论文内容
中文总结 AI 辅助
本研究通过贝叶斯框架结合ET-CE探测器网络，量化不同低频截止频率下z≥15的第三星族双黑洞遗迹的测量不确定性，发现5 Hz配置可提升红移推断精度与探测范围，减小天空定位误差。
中文摘要 AI 辅助
目前LIGO、Virgo和KAGRA探测到的最远引力波（GW）事件是红移z~1.1的双黑洞（BBH）并合，对应光度距离D_L~8 Gpc。下一代GW探测器爱因斯坦望远镜（ET）和宇宙探索者（CE）将探测到恒星形成峰值z_peak~2之外的并合事件，从而直接探测早期宇宙中第一代恒星的遗迹。要实现这一科学潜力，需要精确推断最远并合事件的红移、天空定位和内禀属性。本研究采用完全贝叶斯框架和天体物理动机模型，利用ET-CE探测器网络研究第三星族遗迹，并量化z≥15的双黑洞的红移、天空定位、内禀质量和自旋的测量不确定性。考虑探测器灵敏度的乐观（5 Hz）和悲观（10 Hz）低截止频率，结果显示5 Hz配置可持续提升自旋进动双黑洞的红移推断精度；源帧组分质量平均可测量至约12%的精度，且该族群中最高红移源可被可靠表征，而黑洞自旋仅能获得适度约束。此外，提升的低频灵敏度还扩展了探测器网络的红移探测范围：5 Hz配置下注入的真实红移z_true≃19.8的事件，可在90%置信度下被可靠识别为起源于z≃18.5之外，而10 Hz配置的最大红移下界仅为z≃17.5；10 Hz以下灵敏度的提升还减小了天空定位不确定性，这对宇宙学交叉关联至关重要。
英文摘要
The most distant gravitational-wave (GW) detection by LIGO, Virgo and KAGRA so far is a binary black hole (BBH) merger at a redshift of $z\sim 1.1$, corresponding to a luminosity distance of $D_L \sim 8 \, \rm Gpc$. The next-generation GW detectors, the Einstein Telescope (ET) and Cosmic Explorer (CE), will detect mergers beyond the peak of star formation at $z_{\rm peak}\sim 2$, enabling the direct detection of the remnants of the first stars in the early Universe. Realising this science potential requires accurate inference of the redshift, sky localization and intrinsic properties of the most distant mergers. In this work, using a fully Bayesian framework and an astrophysically motivated model, we study Population III remnants with an ET-CE detector network and quantify the measurement uncertainties in redshift, sky localisation, intrinsic masses and spins for BBHs at $z \geq 15$. Considering an optimistic ($5\, \rm Hz$) and pessimistic ($10\,\rm Hz$) lower cutoff frequency for the detectors' sensitivity, we show that the $5\, \rm Hz$ configuration consistently improves the redshift inference for spin-precessing binaries. We also find that the source-frame component masses can be measured to within $\sim 12\%$ on average, and that the highest-redshift sources in the population can be reliably characterised. In contrast, we find only modest constraints on the BH spins. The improved low-frequency sensitivity also extends the redshift reach of the detector network, enabling events injected at $z_{\rm true}\simeq19.8$ to be confidently identified as originating beyond $z\simeq18.5$ at $90\%$ credibility, compared to a maximum lower-bound redshift of $z\simeq17.5$ for the $10\,\rm Hz$ configuration. Improved detector sensitivity below $10\, \rm Hz$ also reduces the sky-localisation uncertainties, which are essential for cosmological cross-correlation.
