Deconvolving Pulsar Signals with Cyclic Spectroscopy: A Systematic Evaluation
Deconvolving Pulsar Signals with Cyclic Spectroscopy: A Systematic Evaluation
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DOI：
10.3847/1538-4357/abf48b
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发表时间：
2020-08
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通讯作者：
T. Dolch;D. Stinebring;Glenn Jones;Hengrui Zhu;R. Lynch;T. Cohen;P. Demorest;M. Lam;L. Levin;M. Mclaughlin;N. Palliyaguru
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作者：
T. Dolch;D. Stinebring;Glenn Jones;Hengrui Zhu;R. Lynch;T. Cohen;P. Demorest;M. Lam;L. Levin;M. Mclaughlin;N. Palliyaguru
无线电脉冲星信号通过电离的星际介质传播时会受到显著的扰动。除了由于色散而导致的依赖于频率的脉冲到达时间之外，脉冲形状也被扭曲和移位，被不均匀的星际等离子体散射，影响脉冲到达时间。了解散射影响脉冲星定时的程度对于使用脉冲星定时阵列（PTA）进行引力波探测非常重要，因为脉冲星定时阵列依赖于脉冲星作为稳定时钟的可靠性，其不确定性在100年或更长时间内为100 ns或更小。散射可以被描述为固有脉冲形状与表示多径传播效应的脉冲响应函数的卷积。在以前的研究中，循环光谱技术已被应用到脉冲星信号去卷积的散射从原始发射信号的影响，提高整体定时精度。我们提出了一个模拟数据的分析，以测试质量的反卷积使用循环光谱在一系列参数表征星际散射和脉冲星的信号噪声比（S/N）。我们表明，循环光谱是最有效的高S/N和/或高度散射的光谱。我们的结论是，循环光谱可以发挥重要的作用，在散射校正到遥远的人口的高度散射的恒星目前不包括在PTA。对于未来的望远镜和现有的仪器，如升级了超宽带接收器的绿色银行望远镜，循环光谱可能会使PTA质量的望远镜数量增加一倍。
Radio pulsar signals are significantly perturbed by their propagation through the ionized interstellar medium. In addition to the frequency-dependent pulse times of arrival due to dispersion, pulse shapes are also distorted and shifted, having been scattered by the inhomogeneous interstellar plasma, affecting pulse arrival times. Understanding the degree to which scattering affects pulsar timing is important for gravitational-wave detection with pulsar timing arrays (PTAs), which depend on the reliability of pulsars as stable clocks with an uncertainty of ∼100 ns or less over ∼10 yr or more. Scattering can be described as a convolution of the intrinsic pulse shape with an impulse response function representing the effects of multipath propagation. In previous studies, the technique of cyclic spectroscopy has been applied to pulsar signals to deconvolve the effects of scattering from the original emitted signals, increasing the overall timing precision. We present an analysis of simulated data to test the quality of deconvolution using cyclic spectroscopy over a range of parameters characterizing interstellar scattering and pulsar signal-to-noise ratio (S/N). We show that cyclic spectroscopy is most effective for high S/N and/or highly scattered pulsars. We conclude that cyclic spectroscopy could play an important role in scattering correction to distant populations of highly scattered pulsars not currently included in PTAs. For future telescopes and for current instruments such as the Green Bank Telescope upgraded with the ultrawide bandwidth receiver, cyclic spectroscopy could potentially double the number of PTA-quality pulsars.