标题： 提高对原初随机引力波的探测灵敏度，减少天体物理前景。 二。 亚阈值双中子星 显示英文标题

标题： Improving the detection sensitivity to primordial stochastic gravitational waves with reduced astrophysical foregrounds. II. Subthreshold binary neutron stars

摘要： 随机引力波（GWs）由早期宇宙过程产生的原初成分和由致密双星合并产生的天体物理成分组成。 为了探测原初随机引力波背景（SGWB），必须将天体物理前景减少到高精度，这在第三代（3G）地面引力波探测器中是可行的。 先前的研究表明，从单独可检测的合并事件中产生的前景可以减少到低于$10^{-3}$的剩余能量密度，如果未妥善清理，来自亚阈值双中子星（BNSs）的剩余前景将成为瓶颈。 在本工作中，我们提出可以通过基于种群的方法，利用所有BNSs的各向同性轨道取向，即$\cos\iota$中的均匀分布，来估计亚阈值BNSs的前景能量密度$\Omega_{\rm sub}$，其中$\iota$是BNSs相对于视线方向的倾角。 使用这种方法，我们发现假设在我们的模拟中有$O(10^5)$个单独检测到的BNSs，$\Omega_{\rm sub}$可以以百分之一的不确定性进行测量。 这种方法代表了一种有前途的解决前景清理问题的方法。 显示英文摘要

摘要： Stochastic gravitational waves (GWs) consist of a primordial component from early Universe processes and an astrophysical component from compact binary mergers. To detect the primordial stochastic GW background (SGWB), the astrophysical foregrounds must be reduced to high precision, which is achievable for third-generation (3G) ground based GW detectors. Previous studies have shown that the foreground from individually detectable merger events can be reduced with fractional residual energy density below $10^{-3}$, and the residual foreground from subthreshold binary neutron stars (BNSs) will be the bottleneck if not well cleaned. In this work, we propose that the foreground energy density of subthreshold BNSs $\Omega_{\rm sub}$ can be estimated via a population based approach from the individually detectable BNSs utilizing the isotropic orbital orientations of all BNSs, i.e., uniform distribution in $\cos\iota$, where $\iota$ is the BNS inclination angle with respect to the line of sight. Using this approach, we find $\Omega_{\rm sub}$ can be measured with percent-level uncertainty, assuming $O(10^5)$ individually detected BNSs in our simulations. This method represents a promising approach to tackling the foreground cleaning problem.