Plasma environment effects on K lines of astrophysical interest

Aims . In the context of accretion disks around black holes, we estimate plasma-environment effects on the atomic parameters associated with the decay of K-vacancy states in highly charged iron ions, namely Fe XVII – Fe XXV . Methods . Within the relativistic multiconfiguration Dirac–Fock (MCDF) framework, the electron–nucleus and electron–electron plasma screenings were approximated with a time-averaged Debye–Hückel potential. Results . Modified ionization potentials, K thresholds, wavelengths, radiative emission rates, and Auger widths are reported for astrophysical plasmas characterized by electron temperatures and densities in the ranges 10 5 − 10 7 K and 10 18 − 10 22 cm −3 , respectively. Conclusions . We conclude that the high-resolution microcalorimeters on board future X-ray missions such as XRISM and ATHENA are expected to be sensitive to the lowering of the iron K edge due to the extreme plasma conditions occurring in accretion disks around compact objects.