Authors: Chengcai Shen (CfA), John C. Raymond (CfA), Nicholas A. Murphy (CfA)

Nonequilibrium ionization (NEI) is essentially required for astrophysical plasma diagnostics once the plasma status departs from the assumption of ionization equilibrium. In this work, we perform NEI analysis combined with magnetohydrodynamic (MHD) simulations of Petschek-type magnetic reconnection current sheets during solar eruptions. The results show that under-ionized features can be commonly found in shocked reconnection outflows and thermal halo regions outside the shocks. The departure from equilibrium ionization strongly depends on plasma density. Moreover, the departure is also impacted by the observed temperature of the target: the high-temperature Fe ions are strongly affected by the effects of NEI. The under-ionization also affects the synthetic SDO/AIA intensities, which indicates that the reconstructed hot reconnection current sheet structure may be significantly underestimated either for temperature or apparent width. Finally, we show the potential reversal between the under-ionized and over-ionized states at the lower tip of current sheets above flare loops, which can strongly affect multiple SDO/AIA band ratios.