Exploring the Asymmetry of the Solar Corona Electron Density with Very Long Baseline Interferometry

TL;DR

This paper demonstrates that Very Long Baseline Interferometry (VLBI) can effectively probe the asymmetry of the solar corona's electron density, offering a new observational approach to compare and validate different solar corona models.

Contribution

It introduces an improved 3D numerical model for the solar corona's electron density and shows VLBI's capability to distinguish between asymmetric density models.

Findings

VLBI observations are sensitive to the electron density of the solar corona.

VLBI can differentiate between symmetric and asymmetric electron density models.

The proposed 3D model enhances the understanding of coronal asymmetries.

Abstract

The Sun's corona has interested researchers for multiple reasons, including the search for solution for the famous coronal heating problem and a purely practical consideration of predicting geomagnetic storms on Earth. There exist numerous different theories regarding the solar corona; therefore, it is important to be able to perform comparative analysis and validation of those theories. One way that could help us move towards the answers to those problems is the search for observational methods that could obtain information about the physical properties of the solar corona and provide means for comparing different solar corona models. In this work we present evidence that VLBI observations are, in certain conditions, sensitive to the electron density of the solar corona and are able to distinguish between different electron density models, which makes the technique of VLBI valuable for solar corona investigations. Recent works on the subject used a symmetric power-law model of the electron density in solar plasma; in this work, an improvement is proposed based on a 3D numerical model.