Non-Equilibrium Ionization Plasma During Large Solar Limb Flare Observed by Hinode/EIS

TL;DR

This paper investigates the non-equilibrium ionization processes in plasma during a large solar flare, revealing how ion ratios and turbulence evolve downstream of reconnection outflows using Hinode/EIS observations.

Contribution

It provides observational evidence of time-dependent ionization effects and turbulence reduction in solar flare plasma, enhancing understanding of flare dynamics.

Findings

FeXXIV / FeXXIII ratios increase downstream of reconnection

Non-thermal velocity decreases significantly along the outflow

Time-dependent ionization consistent with constant Te = 25 MK

Abstract

This study on plasma heating considers the time-dependent ionization process during a large solar flare on September 10, 2017, observed by Hinode/EIS. The observed FeXXIV / FeXXIII ratios increase downstream of the reconnection outflow, and they are consistent with the time-dependent ionization effect at a constant electron temperature Te = 25 MK. Moreover, this study also shows that the non-thermal velocity, which can be related to the turbulent velocity, reduces significantly along the downstream of the reconnection outflow, even when considering the time-dependent ionization process.