Constraints of temperature and density of plasma in non-equilibrium ionization state

During a major solar eruption, the erupting plasma is possibly out of the equilibrium ionization state because of its rapid heating or cooling. The non-equilibrium ionization process is important in a rapidly evolving system where the thermodynamical time scale is shorter than the ionization or recombination time scales. We investigate the effects of non-equilibrium ionization on EUV and X-ray observations by the Atmospheric Imaging Assembly (AIA) on board Solar Dynamic Observatory and X-ray Telescope (XRT) on board Hinode. For the investigation, first, we find the emissivities for all the lines of ions of elements using CHIANTI 8.07, and then we find the temperature responses multiplying the emissivities by the effective area for each AIA and XRT passband. Second, we obtain the ion fractions using a time-dependent ionization model (Shen et al. 2015), which uses an eigenvalue method, for all the ions, as a function of temperature and a characteristic time scale, n_et, where n_e and t are density and time, respectively. Lastly, the ion fractions are multiplied by the temperature response for each passband, which results in a 2D grid for each combination of temperature and the characteristic time scale. This is the set of passband responses for plasma that is rapidly ionized in a current sheet or a shock. We find that most of the ions reach to the equilibrium at the smaller values of the n_et = 1x10¹² cm^-3s. We utilize the set of responses to estimate the temperature and density for a shock plasma associated with a coronal mass ejection on 2010 June 13. We find that the constraints of the temperature and density of the shock plasma are 6.8 MK - 13.5 MK and 1.6x10⁷ - 2.8x10⁷ cm^-3, respectively.