  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 are
approximated with a time-averaged Debye-Huckel 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 respectively in the ranges 1E5 - 1E7 K and 1E18 -
1E22 cm-3 . Conclusions. We conclude that the high-resolution
micro-calorimeters onboard 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.
