Spectral analysis of 3D MHD models of coronal structures

TL;DR

This paper uses 3D MHD models with enhanced magnetic flux to analyze EUV emission lines, aiming to understand coronal heating and compare stellar activity levels.

Contribution

It introduces a numerical experiment with increased magnetic flux to study coronal signatures, highlighting differences between the Sun and more active stars.

Findings

Signatures in EUV emission lines vary with magnetic activity levels.

Model results show how flux braiding influences coronal heating signatures.

Comparison with observations helps validate the MHD models.

Abstract

We study extreme-ultraviolet emission line spectra derived from three-dimensional magnetohydrodynamic models of structures in the corona. In order to investigate the effects of increased magnetic activity at photospheric levels in a numerical experiment, a much higher magnetic flux density is applied at photospheric levels as compared to the Sun. Thus, we can expect our results to highlight the differences between the Sun and more active, but still solar-like stars. We discuss signatures seen in extreme-ultraviolet emission lines synthesized from these models and compare them to signatures found in the spatial distribution and temporal evolution of Doppler shifts in lines formed in the transition region and corona. This is of major interest to test the quality of the underlying magnetohydrodynamic model to heat the corona, i.e. currents in the corona driven by photospheric motions (flux braiding).