In pulsar astronomy, detecting effective pulsar signals among numerous pulsar candidates is an important research topic. Starting from space X-ray pulsar signals, the two-dimensional autocorrelation profile map (2D-APM) feature modelling method, which utilizes epoch folding of the autocorrelation function of X-ray signals and expands the time-domain information of the periodic axis, is proposed. A uniform setting criterion regarding the time resolution of the periodic axis addresses pulsar signals without any prior information. Compared with the traditional profile, the model has a strong anti-noise ability, a greater abundance of information and consistent characteristics. The new feature is simulated with double Gaussian components, and the characteristic distribution of the model is revealed to be closely related to the distance between the double peaks of the profile. Next, a deep convolutional neural network (DCNN) is built, named Inception-ResNet. According to the order of the peak separation and number of arriving photons, 30 data sets based on the Poisson process are simulated to construct the training set, and the observation data of PSRs B0531+21, B0540-69 and B1509-58 from the Rossi X-ray Timing Explorer (RXTE) are selected to generate the test set. The number of training sets and the number of test sets are 30,000 and 5,400, respectively. After achieving convergence stability, more than 99$\%$ of the pulsar signals are recognized, and more than 99$\%$ of the interference is successfully rejected, which verifies the high degree of agreement between the network and the feature model and the high potential of the proposed method in searching for pulsars.
The GMRT High Resolution Southern Sky Survey for pulsars and transients -- III: searching for long period pulsars
在理想白噪声背景下，利用全相位相干快速折叠算法（FFA）搜索周期性非加速信号，理论上比非相干谐波求和快速傅里叶变换（FFT）搜索更灵敏。在本文中，我们提出了一个FFA搜索实现使用RIPTIDE和FFT搜索实现使用PRESTO的性能比较，在一个范围内的信号参数与白噪声和真正的望远镜噪声从GHRSS调查与uGMRT。我们发现，FFA搜索与适当的去红的时间序列，表现出更好的比FFT搜索与频谱白化的长周期序列在真正的GHRSS噪声条件。我们描述了一个FFA搜索管道实施的GHRSS调查寻找在0.1秒至100秒的时间范围内，高达500 pc cm $^{-3}$的分散措施的雷达。我们使用该管道处理了覆盖天空$^2$的$\sim$ 1500度的GHRSS测量数据。我们重新检测了43个已知的信号，FFA搜索比FFT搜索具有更好的信噪比。我们还报告发现了两个新的脉冲星，包括一个长周期脉冲星，具有短的占空比与FFA搜索管道。周期为几秒或更长的长周期脉冲星的数量有助于限制脉冲星的死亡线。
Searching for a waveform-agnostic gravitational wave signal in pulsar timing arrays
Columbia University（哥伦比亚大学）；University of Birmingham（伯明翰大学）；Monash University（蒙纳士大学）；Montana State University（蒙大拿州立大学）；Oregon State University（俄勒冈州立大学）
QuickGWecc: Fast Bayesian pipeline for searching eccentric binaries in pulsar timing array data
Foundation for Research & Technology – Hellas（希腊研究与技术基金会）；University of Birmingham（伯明翰大学）；Indian Institute of Science Education and Research Thiruvananthapuram（印度科学教育与研究学院特里凡得琅分校）；Washington State University（华盛顿州立大学）
