Photoionization And Resonant Ionization Data For K-shell in Highly Charged Iron Ions

Iron K-shell lines are among the most prominent features in astronomical X-ray spectra. These lines are
observed in a wide variety of natural X-ray sources, including active galactic nuclei, X-ray binaries, stellar
corona, and supernova remnants. This project is dedicated to the continued development of relativistic
computational methods to generate high-precision atomic data for iron ions. The goal of the project
is to model Kα, Kβ, and Kγ lines from iron ions, as well as the ionisation rates. To do this, we
compute direct photoionization and resonant ionization cross-sections for both valence and inner-shell
electrons. The initial emphasis will be on iron ions in the highly charged states Fe XVII through Fe XXVI,
which dominate X-ray emissions in many hot cosmic environments. We employ the AUTOSTRUCTURE
computational package, which allows for the calculation of atomic structure and collisional data within a
relativistic framework, using distorted-wave and configuration interaction approaches. These results are
compared against data obtained from the Breit–Pauli R-matrix (BPRM) method. The resulting atomic
data will be of significant value to the astrophysical community, especially for modeling and interpreting
high-resolution X-ray spectra obtained from modern space telescopes.