Sensitivity of new detection method for ultra-low frequency gravitational waves with pulsar spin-down rate statistics
Sensitivity of new detection method for ultra-low frequency gravitational waves with pulsar spin-down rate statistics
复制标题
脉冲星自旋速率统计超低频引力波探测新方法的灵敏度
DOI：
10.1093/mnras/sty976
复制
发表时间：
2018
影响因子：
4.8
通讯作者：
Kuroyanagi Sachiko
中科院分区：
文献类型：
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作者：
Yonemaru Naoyuki;Kumamoto Hiroki;Takahashi Keitaro;Kuroyanagi Sachiko
Yonemaru 等人提出了一种新的超低频引力波（GW）探测方法，其频率远低于脉冲星定时阵列（PTA）的观测范围。在 PTA 分析中，在观测时间跨度内线性演化的超低频引力波 (≲10−10Hz) 被脉冲星自旋下降速率吸收，因为两者对脉冲到达时间具有相同的影响。因此，传统的PTA方法无法检测到此类GW。然而，观测到的自旋下降速率的偏差取决于脉冲星和引力波源的相对方向，并在天空中显示出四极模式。因此，如果我们根据天空中的位置对脉冲星进行划分，并观察自旋速率统计的差异，就可以检测到来自单一来源的超低频引力波。在本文中，我们通过蒙特卡罗模拟评估了该方法的潜力，并估计了灵敏度，仅考虑“地球项”，而“脉冲星项”对于引力波频率 10−13 至 10−10Hz 的作用类似于随机噪声。我们发现，对于未来平方公里阵列巡天有望发现的3000毫秒脉冲星，原则上可以探测到振幅导数约为的引力波。还给出了 Sgr* 和 M87 中可能存在的超大质量双黑洞的含义。
A new detection method for ultra-low-frequency gravitational waves (GWs) with a frequency much lower than the observational range of pulsar timing arrays (PTAs) was suggested in Yonemaru et al. In the PTA analysis, ultra-low-frequency GWs (≲10−10Hz) which evolve just linearly during the observation time span are absorbed by the pulsar spin-down rates since both have the same effect on the pulse arrival time. Therefore, such GWs cannot be detected by the conventional method of PTAs. However, the bias on the observed spin-down rates depends on relative direction of a pulsar and GW source and shows a quadrupole pattern in the sky. Thus, if we divide the pulsars according to the position in the sky and see the difference in the statistics of the spin-down rates, ultra-low-frequency GWs from a single source can be detected. In this paper, we evaluate the potential of this method by Monte Carlo simulations and estimate the sensitivity, considering only the ‘Earth term’ while the ‘pulsar term’ acts like random noise for GW frequencies 10−13to 10−10Hz. We find that with 3000 milli-second pulsars, which are expected to be discovered by a future survey with the square kilometre array, GWs with the derivative of amplitude of aboutcan in principle be detected. Implications for possible supermassive binary black holes in Sgr* and M87 are also given.