Global Coronal Plasma Diagnostics Based on Multi-slit EUV Spectroscopy

TL;DR

This paper introduces a multi-slit EUV spectroscopic method for comprehensive, simultaneous solar corona diagnostics, demonstrating its robustness and potential for global monitoring and eruption prediction.

Contribution

A novel multi-slit EUV spectrometer design and an optimized disambiguation method for accurate global plasma diagnostics of the solar corona.

Findings

Good agreement between modeled and inverted parameters during CME eruption

Robust spectral decomposition method validated for corona diagnostics

Potential for real-time global solar monitoring

Abstract

Full-disk spectroscopic observations of the solar corona are highly desired to forecast solar eruptions and their impact on planets and to uncover the origin of solar wind. In this paper, we introduce a new multi-slit design (5 slits) to obtain extreme ultraviolet (EUV) spectra simultaneously. The selected spectrometer wavelength range (184-197 \r{A}) contains several bright EUV lines that can be used for spectral diagnostics. The multi-slit approach offers an unprecedented way to efficiently obtain the global spectral data but the ambiguity from different slits should be resolved. Using a numerical simulation of the global corona, we primarily concentrate on the optimization of the disambiguation process, with the objective of extracting decomposed spectral information of six primary lines. This subsequently facilitates a comprehensive series of plasma diagnostics, including density (Fe XII 195.12/186.89 \r{A}), Doppler velocity (Fe XII 193.51 \r{A}), line width (Fe XII 193.51 \r{A}) and temperature diagnostics (Fe VIII 185.21 \r{A}, Fe X 184.54 \r{A}, Fe XI 188.22 \r{A}, Fe XII 193.51 \r{A}). We find a good agreement between the forward modeling parameters and the inverted results at the initial eruption stage of a coronal mass ejection, indicating the robustness of the decomposition method and its immense potential for global monitoring of the solar corona.