| Name: | Puja Majee |
| Affiliation: | National Centre for Radio Astrophysics |
| Conference ID: | ASI2025_342 |
| Title: | Unveiling the Coronal Condition for Generation of Type-II Solar Radio Bursts through MHD Simulations and Radio Imaging |
| Authors: | Puja Majee 1, Nishtha Sachdeva 2, Divya Oberoi 1 |
| Authors Affiliation: | 1 National Centre for Radio Astrophysics, Pune, India
2 Department of Climate and Space Sciences and Engineering, University of Michigan, USA |
| Mode of Presentation: | Oral |
| Abstract Category: | Sun, Solar System, Exoplanets, and Astrobiology |
| Abstract: | Metric type-II solar radio bursts are plasma emissions, mostly associated with CME-driven shocks, and hence can be used as remote probes for the kinematics and dynamics of the CMEs at lower coronal heights. Association with the potent driver of the space weather, CMEs, makes these radio emissions very interesting from the perspective of space weather. However, not every CME gives rise to these emissions. While the spectroscopic imaging studies of type-IIs are rare, almost all have revealed that the type-II sources are localized on the extended shock front. This implies that certain conditions need to be satisfied to generate these plasma emissions. To explore this aspect, high-fidelity radio image-based information along with EUV, whitelight observations, and coronal density models are essential. While only a few studies have been done regarding this aspect, a majority of them conclude that for the generation of a type-II emission, the shock needs to be supercritical and the shock geometry needs to be quasi-perpendicular, i.e. the angle between the shock normal and the upstream magnetic field should exceed 45o. To verify this, we have carried out a detailed comparison between high-fidelity radio images from the precursor of the low-frequency telescope of the Square Kilometre Array Observatory, the Murchison Widefield Array (MWA) with the simulations from a physics-based, data-driven self-consistent MHD model, Alfven Wave Solar-atmosphere Model (AWSoM) within the Space Weather Modeling Framework (SWMF). The detailed plasma parameters provided by AWSoM allow us to identify expected source regions where the shock is supercritical and has a quasi-perpendicular geometry, along with the local plasma frequency. These two excellent tools thus provide all of the ingredients needed for comparing observations against expectations. This presentation will summarize the results of this effort and mark interesting progress toward understanding the conditions for generating type II radio emissions.
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