Solar energetic particles and their association with radio emissions

TL;DR

This paper discusses how high-resolution radio imaging, especially with SKA, combined with spacecraft data, can improve understanding of solar energetic particle acceleration, escape, and their association with radio emissions.

Contribution

It highlights the potential of SKA radio observations to elucidate the origins and acceleration mechanisms of solar energetic particles and their link to radio bursts.

Findings

SKA can determine acceleration time, trajectory, and escape of electrons.

Radio observations can distinguish between flare and shock acceleration.

Synergy with spacecraft data enhances understanding of SEP origins.

Abstract

Energetic particle populations are ubiquitous throughout the Universe. In our solar system, the most prominent sources of energetic particles are solar flares or collisionless shocks often driven by huge eruptions of magnetised plasma called coronal mass ejections (CMEs). Remotely, low energy electrons from the Sun can be observed as solar radio bursts that are produced by accelerated electron beams undergoing beam-plasma interactions. There are still many open questions on the generation of solar energetic particles (SEP): how and where are SEPs accelerated during solar flares and CMEs and how they escape the solar atmosphere? Another important question is: what is the link between the solar radio bursts and the observed SEPs at spacecraft? SKA can provide high-resolution radio images combined with spectroscopic observations to determine the acceleration time, trajectory and escape of low energy electrons from the solar corona. The synergy between SKA and current space missions will help investigate solar activity and energetic particles across a wide range of wavelengths and particle energies. Particle data from spacecraft can be used to make a connection between radio bursts and SEPs by comparing SEP inferred injection times and energies to those of electrons generating radio bursts at the Sun. Radio observations in turn can be used to distinguish between flare and shock acceleration since different radio bursts pinpoint towards different energetic processes. Since the acceleration region and origin of SEPs of various properties is still largely debated, radio observations have the potential to be an invaluable tool in unraveling these processes.