论文标题
GMRT高分辨率南部天空调查脉冲星和瞬变 - iii：寻找长时间的脉冲星
The GMRT High Resolution Southern Sky Survey for pulsars and transients -- III: searching for long period pulsars
论文作者
论文摘要
在理想的快速折叠算法（FFA）存在理想的白噪声的情况下，在理想的白噪声下搜索周期性的非加速信号，理论上是一种比快速的傅立叶变换（FFT）搜索更敏感的搜索方法。在本文中，我们介绍了使用Riptide和使用Presto进行FFA搜索实现的性能的比较，在具有白噪声的一系列信号参数以及与UGMRT的GHRSS调查中的真实望远镜噪声相比。我们发现，通过适当的时间序列进行FFA搜索，在实际GHRSS噪声条件下，长期脉冲星的光谱美白性能比FFT搜索更好。我们描述了针对GHRSS调查实施的FFA搜索管道，寻找在0.1 s至100 s的周期范围内，并达到500 pc cm $^{ - 3} $的分散度量。我们处理了GHRSS调查数据涵盖$ \ sim $ 1500度$^2 $的天空，并使用此管道。在FFA搜索中，我们重新发现了43个具有更好信噪比的已知脉冲星，而不是在FFT搜索中。我们还报告发现了两个新的脉冲星，其中包括长时间的脉冲星，该FFA搜索管道具有短期职责。长期脉冲星的人口为几秒钟或更高，可以帮助限制脉冲星的死亡线。
Searching for periodic non-accelerated signals in presence of ideal white noise using the fully phase-coherent Fast Folding Algorithm (FFA) is theoretically established as a more sensitive search method than the Fast Fourier Transform (FFT) search with incoherent harmonic summing. In this paper, we present a comparison of the performance of an FFA search implementation using RIPTIDE and an FFT search implementation using PRESTO, over a range of signal parameters with white noise and with real telescope noise from the GHRSS survey with the uGMRT. We find that FFA search with appropriate de-reddening of time series, performs better than FFT search with spectral whitening for long period pulsars in real GHRSS noise conditions. We describe an FFA search pipeline implemented for the GHRSS survey looking for pulsars over a period range of 0.1 s to 100 s and up to dispersion measure of 500 pc cm$^{-3}$. We processed GHRSS survey data covering $\sim$ 1500 degree$^2$ of the sky with this pipeline. We re-detected 43 known pulsars with better signal-to-noise in the FFA search than in the FFT search. We also report discovery of two new pulsars including a long period pulsar having a short duty-cycle with this FFA search pipeline. The population of long period pulsars with periods of several seconds or higher can help to constrain the pulsar death-line.
