Thursday

Solar type III radio bursts contain a wealth of information about electron dynamics. They provide the best remote sensing diagnostics of electron beams escaping from the Sun and can simultaneously provide parameters of the solar corona and solar wind plasma they travel through. Studies routinely use type III bursts to estimate the bulk velocity of escaping electron beams from the Sun. However, the motion of different regions of an electron beam (front, middle and back) have never been systematically analysed before. We present our electron beam dynamics results which utilise both the high-resolution LOFAR observations and numerical simulations of escaping solar electron beam propagation through the solar corona. We show how type III frequency drift rates have rise times decay times, driven by electron beam speeds being faster at the front of the beam and slower at the back. The difference in speed naturally elongates the beam in space. The energy density of electron beams strongly dictates their speed and expansion, and produces type IIIs with higher peak brightness temperatures. Higher background plasma temperatures also increase beam speeds, particularly at the back of the beam. Our radial predictions can be tested by the upcoming in situ measurements made by Solar Orbiter and Parker Solar Probe.