Determining the possible acceleration regions of in situ electrons using space- and ground-based radio observations

Energetic particles in the heliosphere are produced by flaring processes on the Sun or shocks driven by coronal mass ejections. These particles can be detected remotely through the electromagnetic radiation they generate (X-rays or radio emission) or in situ by spacecraft monitoring the Sun and the heliosphere. Here, we investigate the acceleration location, escape, and propagation directions of electron beams producing radio bursts observed with the Low Frequency Array (LOFAR), Parker Solar Probe (PSP) and Solar Orbiter (SolO) and compare it to hard X-ray (HXR) emission and in situ electrons observed at SolO. These observations are combined with a three-dimensional (3D) representation of the electron acceleration locations and results from a magneto-hydrodynamic (MHD) model of the solar corona in order to determine the connectivity to Solar Orbiter and relate the electrons observed remotely to in situ electrons. We observed a long-duration metric-decametric type II radio burst with good connectivity to Solar Orbiter, which also observed a significant in situ electron event. The injections times of the in situ electrons are simultaneous with the onset of the type II radio burst. The properties of the SolO electrons also indicate that shock acceleration is likely the main contributor to the observed fluxes, with a possible smaller contribution coming from the flare, given the presence of HXRs and type III radio bursts.