Speaker
Description
Observing the Sun in the radio domain is a powerful tool to detect and study the presence of shock waves in the solar corona, especially in the absence of other clear observations of coronal mass ejections (CMEs) capable of driving these shocks. Electrons accelerated by coronal shocks can be remotely detected through the radio waves that they emit in the form of type II solar radio bursts. In this study, we investigate the source locations of three type II bursts using imaging and spectroscopic observations with the Low Frequency Array (LOFAR). The type II bursts occur in the absence of a notable CME, with only a faint and narrow eruption observed at other wavelengths. The type II bursts, however, indicate the presence of a shock wave and multiple periods of electron acceleration despite the presence of a weak CME. By tracking the spatial and temporal evolution of the type II radio sources over multiple frequencies, we find that the three type II bursts are generated in separate and distinct regions. We also extend the analysis into three dimensions by combining LOFAR imaging with a magnetohydrodynamic (MHD) model of the solar corona to investigate the properties of the emission regions of these type II bursts.
