Parkes observations for project P1008 semester 2019APRS_03

Magnetic field measurements of the Solar wind (SW) are extremely challenging, especially at close angular distances from the Sun. If they are obtained by measuring Faraday rotation of the radiation of background sources like active galactic nuclei, they are typically dependent on models of the electron density distribution in the heliosphere. However, pulsars can provide simultaneous, model-independent measurements of the electron density along the line-of-sight, along with Faraday Rotation estimates, and thus direct measurements of the SW magnetic field. \r\nMoreover, high-precision pulsar timing experiments such as Pulsar Timing Arrays (PTAs) can be strongly affected by the free electron distribution in the SW, and it is fundamentally important to understand, model and mitigate its influence on PTAs signals.\r\nWith this proposal we aim to obtain high-cadence and precise measurements of the magnetic field and the electron density distribution of the SW by tracking three pulsars with low- to mid-ecliptic latitudes during their Solar approaches, and to reconstruct the SW dependence on the heliographic latitude. This will allow us to characterise the magnetic field of the SW and to collect precious information about the short-term fluctuations in the electron density that can appear as correlated noise in PTAs.