FeII-FeVIII K lines Plasma environment effects

We use the fully relativistic multiconfiguration Dirac-Fock (MCDF) method approximating the plasma electron-nucleus and electron-electron screenings with a time-averaged Debye-Huckel potential. Results.

Modified ionization potentials, K-threshold energies, wavelengths, radiative emission rates, and Auger widths are reported for plasmas characterized by electron temperatures and densities in the ranges 10^5^-10^7^K and 10^18^-10^22^cm^-3^. In addition, we propose two universal fitting formulae to predict the IP and K-thresold lowerings in any elemental ion. We conclude that the high-resolution X-ray spectrometers onboard the future XRISM and ATHENA space missions will be able to detect the lowering of the K edges of these Fe ions due to the extreme plasma conditions occurring in accretion disks around compact objects.