标题： 未来地面引力波探测器网络观测运行中轻型致密双星合并的探测概率 显示英文标题

标题： Detection probability of light compact binary mergers in future observing runs of the current ground-based gravitational wave detector network

摘要： 尽管在LIGO-Virgo-KAGRA（LVK）引力波探测器网络的第四次观测运行（O4）期间尚未检测到双中子星（BNS）合并，尽管相对于O3结束时的时间体积（VT）增加了三倍以上，一个紧迫的问题是，在运行剩余部分检测到至少一次BNS合并的可能性有多大。 我在这里提出了一种简单且通用的方法来解决此类问题，这是在O4a和O4b部分运行之间的休整期间，LVK公共警报用户指南中所提出的预测的基础。 该方法同样适用于中子星-黑洞（NSBH）合并，其基础是简单的泊松统计以及对未来运行所覆盖的VT与之前运行所覆盖VT之比的估计。 该方法的一个吸引人的优点是其预测独立于合并致密双星的质量分布，而目前该分布非常不确定。 结果不出所料地表明，O4最后阶段最可能的结果是没有检测到任何BNS合并。 然而，检测到非零数量的可能性为34-46%。 对于NSBH合并，至少检测到一次的可能性为64-71%。 下一次观测运行O5的前景更加乐观，根据当前LVK探测器在运行中的目标灵敏度，预测的数值为$N_\mathrm{BNS,O5}=28_{-21}^{+44}$，NSBH检测数量为$N_\mathrm{NSBH,O5}=65_{-38}^{+61}$（中位数和90%对称可信区间）。 这里提出的计算也导致了LVK本地BNS合并率密度估计值的更新，该估计值考虑了到目前为止O4中未检测到BNS合并的情况，其数值为$2.8\,\mathrm{Gpc^{-3}\,yr^{-1}}\leq R_0\leq 480\,\mathrm{Gpc^{-3}\,yr^{-1}}$。 显示英文摘要

摘要： With no binary neutron star (BNS) merger detected yet during the fourth observing run (O4) of the LIGO-Virgo-KAGRA (LVK) gravitational wave (GW) detector network, despite the time-volume (VT) surveyed with respect to the end of O3 increased by more than a factor of three, a pressing question is how likely the detection of at least one BNS merger is in the remainder of the run. I present here a simple and general method to address such a question, which constitutes the basis for the predictions that have been presented in the LVK Public Alerts User Guide during the hiatus between the O4a and O4b parts of the run. The method, which can be applied to neutron star - black hole (NSBH) mergers as well, is based on simple Poisson statistics and on an estimate of the ratio of the VT span by the future run to that span by previous runs. An attractive advantage of this method is that its predictions are independent from the mass distribution of the merging compact binaries, which is very uncertain at the present moment. The results, not surprisingly, show that the most likely outcome of the final part of O4 is the absence of any BNS merger detection. Still, the probability of a non-zero number of detections is 34-46\%. For NSBH mergers, the probability of at least one additional detection is 64-71\%. The prospects for the next observing run O5 are more promising, with predicted numbers $N_\mathrm{BNS,O5}=28_{-21}^{+44}$, and the NSBH detections to be $N_\mathrm{NSBH,O5}=65_{-38}^{+61}$ (median and 90\% symmetric credible range), based on the current LVK detector target sensitivities for the run. The calculations presented here also lead to an update of the LVK local BNS merger rate density estimate that accounts for the absence of BNS merger detections in O4 so far, that reads $2.8\,\mathrm{Gpc^{-3}\,yr^{-1}}\leq R_0\leq 480\,\mathrm{Gpc^{-3}\,yr^{-1}}$.