Parkes observations for project P1295 semester 2023OCTS_05

We propose observing time with the Parkes telescope to investigate four ``spider" millisecond pulsars (MSPs), PSR J1048+2339 (a redback spider), PSR J1908+2105 (an MSP that occupies a region of parameter space between black widows and redbacks), PSR J2052+1219 and PSR J2256-1024 (black widow spiders). Spider MSPs are commonly seen to exhibit frequency-dependent eclipsing. Observations with wide bandwidth telescopes like Parkes UWL (700-4000 MHz) will be extremely useful to study the eclipse mechanisms in these systems. Eclipse properties of spider MSPs are hitherto unexplored at the frequency regime available with the Parkes UWL receiver. We propose to investigate a sample of 4 MSPs mentioned above (for which polarization has not been studied) with the Parkes telescope using the UWL receiver in full polar mode, which will be addressed with this proposal. One of the aims is to model the eclipse phase spectra using wideband observations of these pulsars in an optically thick-to-thin transitioning regime (optical depth nearly 1), to explore the eclipse mechanism. Observing the possible changes in rotation measure (RM) at eclipse ingress and egress will allow us to probe the magnetic field in the eclipse boundaries. We request to cover nearly one full orbit for each of these MSPs. Thus we propose 23 hours of observing time including time for setup and calibration in each epoch with the Parkes UWL receiver for the investigation of the eclipse mechanism as well as the polarization, profile evolution, and spectra of four spider MSPs.

我们提议使用帕克斯望远镜开展观测，以研究四颗“蜘蛛”毫秒脉冲星（MSPs）：PSR J1048+2339（红背蜘蛛型）、PSR J1908+2105（参数空间介于黑寡妇与红背蜘蛛之间的毫秒脉冲星）、PSR J2052+1219及PSR J2256-1024（黑寡妇蜘蛛型）。蜘蛛毫秒脉冲星通常表现出频率相关的掩食现象。利用帕克斯超宽带接收器（Parkes UWL，700-4000 MHz）这类宽频带望远镜进行观测，将对研究这些系统中的掩食机制极具价值。目前，蜘蛛毫秒脉冲星在帕克斯超宽带接收器覆盖的频率范围内的掩食特性尚未被探索。本提案旨在使用帕克斯望远镜的UWL接收器以全偏振模式，对上述四颗（其偏振特性尚未被研究的）毫秒脉冲星展开观测。研究目标之一是通过这些脉冲星在光学厚到薄的过渡区域（光学深度接近1）的宽带观测，构建掩食相位谱模型，以探索掩食机制；同时，观测掩食进入和退出阶段可能的旋转量（RM）变化，从而探测掩食边界处的磁场。我们请求为每颗毫秒脉冲星覆盖近一个完整轨道周期的观测。因此，本提案申请23小时的观测时间，其中包括每个观测周期内的设备设置与校准时间，使用帕克斯UWL接收器研究四颗蜘蛛毫秒脉冲星的掩食机制、偏振特性、脉冲轮廓演化及光谱特征。