AI 中文总结
本文探究首批可分辨超大质量黑洞双星的性质，优化脉冲星计时观测策略可提升其探测概率，高频次观测更易识别高频双星，相关系统可通过光学巡天开展电磁后续观测。
AI 中文摘要
多个脉冲星计时阵列已报道了纳赫兹引力波背景的证据，该背景被认为源自一组旋近超大质量黑洞双星的信号叠加。验证这一解释的关键测试是搜寻可单独分辨的、其信号高于该背景的双星。本文通过解决两个相关问题研究该可能性：（1）首批可分辨双星的最可能性质是什么；（2）如何优化脉冲星计时观测以最大化其电磁识别的前景。通过模拟受引力波背景证据约束的超大质量黑洞双星种群，并研究每次模拟中最响亮的双星，我们推断出首批可单独分辨系统的预期性质。如果MeerKAT继续其当前观测策略共9年，探测单个双星的概率约为10%-27%；将计时精度提高2倍，该概率变为约11%-28%；将观测频次提高4倍，概率约为12%-30%；同时结合这两项改进，探测概率约为12%-33%。此外，实施高频次观测 campaign 可优先分辨更高频率（≥10 nHz）的系统，其轨道周期更短，相比重复频率低的低频双星，更容易通过电磁观测识别。我们讨论了利用当前高频次全天光学巡天对引力波分辨双星进行电磁后续观测的前景。
英文摘要
Several pulsar timing arrays have reported evidence for a nanohertz gravitational-wave background. This background is thought to arise from the superposition of signals from a population of inspiraling supermassive black hole binaries. A key test of this interpretation is the search for individually resolvable binaries whose signals emerge above this background. Here we investigate this possibility by addressing two related questions: (1) what are the most probable properties of the first resolvable binary; and (2) how can pulsar timing observations be optimized to maximize its prospects for electromagnetic identification? By simulating populations of supermassive black hole binaries constrained by evidence for the gravitational-wave background and studying the loudest binary in each simulation, we infer the expected properties of the first individually resolvable systems. If MeerKAT continues its current observing strategy for a total of 9 years, the probability of detecting an individual binary is $\approx10-27\%$. Improving the timing precision by a factor of two changes this probability to $\approx11-28\%$, whereas increasing the cadence by a factor of four gives $\approx12-30\%$. Combining both improvements yields a detection probability of $\approx12-33\%$. Furthermore, implementing a high-cadence observing campaign preferentially resolves higher-frequency systems ($\gtrsim\unit[10]{nHz}$), whose shorter orbital periods make them considerably easier to identify through electromagnetic observations than lower-frequency binaries that repeat infrequently. We discuss prospects of electromagnetic follow-up of gravitational-wave resolved binaries with current high-cadence all-sky optical surveys.
CommentsSubmitted to ApJ. 23 pages, 14 figures
