论文标题
国际脉冲星定时阵列第二个数据发布：搜索各向同性引力波背景
The International Pulsar Timing Array second data release: Search for an isotropic Gravitational Wave Background
论文作者
论文摘要
我们在国际Pulsar定时阵列的第二个数据发布中搜索了各向同性随机引力浪潮背景，这是北美，欧洲和澳大利亚的全球合作综合幼稚的二十多岁的脉动脉冲脉络运动。在我们的参考搜索中，搜索形式的幂定律应变谱$ h_c = a（f/1 \，\ mathrm {yr}^{ - 1}） $α= -0.5 \ pm 0.5 $，其中不确定性代表95 \％可信区域，使用阵列中脉冲星之间的自动和互相关项中的信息。对于$α= -2/3 $的频谱索引，正如灵感超级质量黑洞二进制的人群所预期的那样，恢复的振幅为$ a = 2.8^{+1.2} _ { - 0.8} \ times10^{ - times10^{ - 15} $。尽管如此，尚无明显的证据表明将发现引力波的起源。我们还以一致的方式分析了来自单个脉冲星定时阵列中的构成数据，并清楚地表明，组合的国际数据集更敏感。此外，我们证明了此组合数据集与最近的单阵列数据集产生可比的限制，这些数据集比组合的组成部分多。未来的国际数据发布将提高对重力波辐射的敏感性，并显着提高检测概率。
We searched for an isotropic stochastic gravitational wave background in the second data release of the International Pulsar Timing Array, a global collaboration synthesizing decadal-length pulsar-timing campaigns in North America, Europe, and Australia. In our reference search for a power law strain spectrum of the form $h_c = A(f/1\,\mathrm{yr}^{-1})^α$, we found strong evidence for a spectrally-similar low-frequency stochastic process of amplitude $A = 3.8^{+6.3}_{-2.5}\times10^{-15}$ and spectral index $α= -0.5 \pm 0.5$, where the uncertainties represent 95\% credible regions, using information from the auto- and cross-correlation terms between the pulsars in the array. For a spectral index of $α= -2/3$, as expected from a population of inspiralling supermassive black hole binaries, the recovered amplitude is $A = 2.8^{+1.2}_{-0.8}\times10^{-15}$. Nonetheless, no significant evidence of the Hellings-Downs correlations that would indicate a gravitational-wave origin was found. We also analyzed the constituent data from the individual pulsar timing arrays in a consistent way, and clearly demonstrate that the combined international data set is more sensitive. Furthermore, we demonstrate that this combined data set produces comparable constraints to recent single-array data sets which have more data than the constituent parts of the combination. Future international data releases will deliver increased sensitivity to gravitational wave radiation, and significantly increase the detection probability.
