Parkes observations for project P1189 semester 2024APRS_04

The study of "space weather" is crucial, given the profound impact of solar wind and Coronal Mass Ejection (CME) phenomena on the solar system, presenting risks to Earth's satellites, the power grid, and civilian infrastructure. Observational studies emphasize the primary influence of magnetic fields on the early eruptive phase of CMEs. Despite advancements, understanding CME magnetic fields, especially at low solar altitudes during initial acceleration, remains limited. Valuable insights can be gained by probing the heliosphere at various distances from the sun through observational methods. In this project, our focus is on establishing baseline measurements for the dispersion measure (DM) and rotation measure (RM) at solar altitudes ($> 20 R_\\odot$). We achieve this through regular monitoring of pulsars at larger solar elongations. Challenges arise, such as the varying trend in measured DM for some pulsars due to low-frequency catalog data, impacting the creation of a DM baseline for high-frequency UWL measurements. Preliminary analyses of observed pulsars indicate promising results, prompting further cross-matching with CME events and focused modeling efforts with robust observational coverage.

空间天气（space weather）研究至关重要。太阳风与日冕物质抛射（Coronal Mass Ejection，CME）现象对太阳系影响深远，会对地球卫星、电网及民用基础设施构成威胁。观测研究强调磁场对日冕物质抛射早期爆发阶段的核心调控作用。尽管相关研究已取得进展，但人们对其磁场的认知仍存在局限，尤其是在初始加速阶段的低太阳高度处。通过在距太阳不同距离处开展日球层观测探测，可获得宝贵的研究启示。本项目旨在建立太阳高度大于20倍太阳半径（>20 R☉）处的色散量（dispersion measure, DM）与旋转量（rotation measure, RM）基准测量值，具体通过对大太阳张角处的脉冲星进行定期监测来实现这一目标。当前面临若干挑战：部分脉冲星的实测色散量因低频星表数据存在变化趋势，这会干扰高频UWL测量所用色散量基准的构建。对已观测脉冲星的初步分析结果显示出良好前景，这推动我们进一步开展与日冕物质抛射事件的交叉匹配研究，并针对完备观测覆盖场景开展针对性建模工作。