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

Dan Aksim, Alexey Melnikov, Dmitry Pavlov, Sergey Kurdubov

The Astrophysical Journal, Volume 885, Number 2 (2019)

DOI: 10.3847/1538-4357/ab499a

Ключевые слова: solar wind, solar corona, space plasma, very long baseline interferometry

Аннотация

The Sun's corona has interested researchers for multiple reasons, including the search for a solution to 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 toward 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 very long baseline interferometry (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 three-dimensional numerical model.