Non-Equilibrium Ionization Calculations in MHD Simulations During a Whole Sun Month
Abstract
Time-dependent ionization is important in astrophysical environments where the thermodynamic time scale is shorter than ionization time scale. In this work, we develop a set of FORTRAN routines to perform fast non-equilibrium ionization calculations based on MHD simulations. Using MHD simulation results, we trace the movements of plasma in a Lagrangian framework, and obtain evolutionary history of temperature and electron density. The time-dependent ionization equations are solved using the eigenvalue method, and an adaptive time-step strategy is used to improve the computational efficiency. We then perform non-equilibrium ionization calculations for a thermodynamic MHD model during Carrington rotation 1913 reported by Mikić et al., and obtain the ion charge composition. We also calculate the intensities of UV lines measured by the Ultraviolet Coronagraph Spectrometer (UVCS) on the Solar and Heliospheric Observatory and compare them with observations.
- Publication:
-
Solar Heliospheric and INterplanetary Environment (SHINE 2014)
- Pub Date:
- June 2014
- Bibcode:
- 2014shin.confE..99S