Parkes observations for project P1238 semester 2024APRS_04

Young and energetic pulsars can power strong pulsar wind nebula (PWN), which can be observed from radio to X-ray and beyond. Thanks to the superior sensitivity of the ASKAP EMU survey, we are able to identify new PWNe in the Galactic plane, and use them to guide our search of radio pulsars. This strategy was demonstrated successful by the recent discoveries of two high dispersion measure (DM) pulsars powering a bow-shocked PWNe. Recently, we analysed several EMU fields covering the Galactic plane and identified another five new PWNe candidates. Here we propose to use the Parkes UWL receiver to carry out targeted search of radio pulsars powering these PWNe. Since these system are located in the Galactic plane and can be distant, we expect them to have large DMs. Such high DMs will lead to strong scattering and smearing and make pulsars undetectable in previous pulsar surveys. The wide frequency coverage of UWL, especially the high frequencies, will allow us to avoid these effects and therefore offer us a better chance to find these pulsars.

年轻且富有活力的脉冲星能够驱动形成强烈的脉冲星风云（pulsar wind nebula, PWN），这类天体可在射电、X射线乃至更宽波段被观测到。得益于澳大利亚平方公里阵列探路者（Australian Square Kilometre Array Pathfinder, ASKAP）的EMU巡天（Evolutionary Map of the Universe, EMU）卓越的灵敏度，我们得以在银道面中识别出新的脉冲星风云，并以此为指引开展射电脉冲星搜寻工作。近期两项发现证实了该策略的有效性：两颗具有高色散量（dispersion measure, DM）的脉冲星分别驱动形成了弓形激波脉冲星风云。最近，我们对多个覆盖银道面的EMU巡天天区开展分析，又识别出5个新的脉冲星风云候选体。据此，我们提出使用帕克斯（Parkes）UWL接收机对这些脉冲星风云所驱动的射电脉冲星开展靶向搜寻。由于这些天体系统位于银道面且距离遥远，我们预期它们具有较大的色散量。如此高的色散量会引发强烈的散射与脉冲展宽效应，使得这些脉冲星在以往的巡天观测中无法被探测到。而UWL接收机的宽频覆盖范围，尤其是高频段覆盖，将帮助我们规避上述效应，从而大幅提升发现这类脉冲星的可能性。