Noise-marginalized optimal statistic: A robust hybrid frequentist-Bayesian statistic for the stochastic gravitational-wave background in pulsar timing arrays
Noise-marginalized optimal statistic: A robust hybrid frequentist-Bayesian statistic for the stochastic gravitational-wave background in pulsar timing arrays
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DOI：
10.1103/physrevd.98.044003
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发表时间：
2018-05
影响因子：
5
通讯作者：
S. Vigeland;K. Islo;S. Taylor;J. Ellis
中科院分区：
文献类型：
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作者：
S. Vigeland;K. Islo;S. Taylor;J. Ellis
观测表明，几乎所有星系的中心都含有超大质量黑洞（SMBH）。当星系合并时，这些SMBH形成SMBH双星（SMBHB），发出低频引力波（GW）。这些源的不相干叠加产生了随机引力波背景（GWB），可以通过脉冲星计时阵列观测到。最佳统计量是 GWB 振幅的频率估计量，专门寻找 GWB 引起的脉冲星之间的空间相关性。在本文中，我们介绍了一种改进的方法来计算边缘化单个脉冲星中红噪声的最佳统计量。我们使用模拟来证明该方法可以更准确地确定 GWB 的强度，并且使用噪声边际化最优统计量来比较单极子、偶极子和 Hellings-Downs (HD) 空间相关性的显着性并执行天空扰乱。
Observations have revealed that nearly all galaxies contain supermassive black holes (SMBHs) at their centers. When galaxies merge, these SMBHs form SMBH binaries (SMBHBs) that emit low-frequency gravitational waves (GWs). The incoherent superposition of these sources produce a stochastic GW background (GWB) that can be observed by pulsar timing arrays. The optimal statistic is a frequentist estimator of the amplitude of the GWB that specifically looks for the spatial correlations between pulsars induced by the GWB. In this paper, we introduce an improved method for computing the optimal statistic that marginalizes over the red noise in individual pulsars. We use simulations to demonstrate that this method more accurately determines the strength of the GWB, and we use the noise-marginalized optimal statistic to compare the significance of monopole, dipole, and Hellings-Downs (HD) spatial correlations and perform sky scrambles.