Simulating Gyrosynchrotron Emission in Coronal Flux Rope (Edin Husidic, KU Leuven)

The Sun is among the most powerful radio sources in the solar system, particularly during solar flares and coronal mass ejections (CMEs), when a variety of burst phenomena appear in the dynamic spectrum, including broadband type~IV emissions. These type IV radio bursts are often attributed to incoherent gyrosynchrotron (GS) radiation from electrons magnetically trapped within CMEs, although coherent plasma processes have also been proposed, leading to ongoing interpretative uncertainties. Physics-based numerical modelling provides a valuable approach to address these open questions and to complement both remote-sensing and in-situ observations.

In this talk, we present a novel multi-tool workflow for simulating GS emission in the solar corona. First, we use the magnetohydrodynamic (MHD) 3D coronal model COCONUT to generate coronal background configurations that incorporate CMEs modelled as flux ropes. We then inject energetic electrons into the flux rope and track their evolution using the particle transport code PARADISE. Finally, the MHD output and electron energy distributions are passed to the Ultimate Fast Gyrosynchrotron Codes, which compute the emission and absorption coefficients along lines of sight to produce the radiation intensities.

The resulting synthetic dynamic spectra reproduce key observational features of type~IV bursts and demonstrate a notable sensitivity to the electron energy distributions, CME properties and viewing geometry. Our results support the interpretation that GS emission is a major contributor to type~IV continua, although additional emission mechanisms cannot be excluded. We highlight the potential of this modelling framework for future applications.