Parkes observations for project P1337 semester 2024OCTS_04

For spider pulsars, the companion is evaporated by the pulsar winds and high-energy emissions, causing material to be blown from the companion, which can result in radio eclipses. Radio observations of these eclipses are key to understanding the properties of the eclipse medium. In this proposal, we aim to study the eclipse phenomena of spider pulsars using the UWL receiver at the Parkes telescope. We have three goals: (a) measure the duration of eclipse across a wide bandwidth. We will study the frequency dependence of the eclipse and analyze the eclipse mechanisms at different observational frequencies, (b) study the depolarization of linear polarization. The depolarization of spider pulsars is proposed to be caused by multipath propagation, where the degree of depolarization is expected to be proportional to $\\exp(f^{-4})$. The UWL observations will allow us to examine this method across a wide bandwidth for the first time, (c) measure dispersion measure (DM) variation at the eclipse boundary. The UWL observations will enable us to measure the DM variation more accurately at the eclipse boundary. This will allow us to estimate the mass loss rate of the companion, providing a timescale over which the companion will be completely destroyed.

蜘蛛脉冲星（spider pulsars）的伴星会受到脉冲星风与高能辐射的蒸发作用，导致伴星物质被吹离，最终引发射电掩食现象。对这类掩食的射电观测，是解析掩食介质特性的核心手段。本观测计划拟借助帕克斯望远镜（Parkes telescope）的UWL接收机，开展蜘蛛脉冲星的掩食现象研究。我们设定了三项研究目标：（a）测定宽频带范围内的掩食持续时长，研究掩食的频率依赖性，并剖析不同观测频率下的掩食物理机制；（b）研究线偏振的退偏振效应。现有研究表明，蜘蛛脉冲星的退偏振现象源于多径传播，其退偏振程度预计与$exp(f^{-4})$呈正比关系。本次UWL观测将首次在宽频带范围内对该理论进行验证；（c）测量掩食边界处的色散量（dispersion measure, DM）变化。UWL观测可帮助我们更精准地测定掩食边界处的DM变化，借此可估算伴星的质量损失率，进而推导出伴星被完全摧毁的时间尺度。