Parkes observations for project P991 semester 2018OCTS_08

Finding radio pulsars orbiting near Sgr A* is a major goal of pulsar surveys with existing telescopes and future telescopes such as the Square Kilometer Array (SKA). The discovery of such pulsars will allow us to measure relativistic effects through timing of pulsars in tight orbits around Sgr A*, to characterise the distribution of dark matter near Sgr A*, to study the stellar population in the GC region and to probe the scattering region around Sgr A*. Although several surveys of the GC region have done, the Ultra-Wideband Low (UWL) receiver provides us a much wider frequency coverage with great sensitivity and therefore it is an excellent chance to revisit the GC region. At around 4GHz, a survey with UWL will achieve a sensitivity significantly higher than previous Parkes and Green Bank surveys, especially for pulsars with short spin periods and high dispersion measures.

利用现有望远镜以及平方公里阵列（Square Kilometer Array, SKA）等未来设备开展的脉冲星巡天研究，其核心目标之一便是搜寻在人马座A*（Sgr A*）附近轨道运行的射电脉冲星。此类脉冲星的成功探测，将为我们提供多重科学研究契机：通过对人马座A*周围紧密轨道上的脉冲星进行计时观测，可精确检验相对论效应、刻画人马座A*附近暗物质的空间分布、研究银心（Galactic Center, GC）区域的恒星族群构成，还可探究人马座A*周围的散射介质区域。尽管此前已针对银心区域开展过多次巡天项目，但超宽带低波段（Ultra-Wideband Low, UWL）接收机具备更宽的频率覆盖范围与优异的探测灵敏度，因此为我们重新开展银心区域巡天提供了绝佳机遇。在约4GHz频段下，搭载UWL接收机的巡天项目所能达到的探测灵敏度，将显著高于此前帕克斯（Parkes）与绿岸（Green Bank）望远镜开展的巡天项目，尤其针对自旋周期较短、色散量（dispersion measures）较高的脉冲星而言优势更为突出。