Accurate and large-scale
datasets of level energies and fine structure transition probabilities
for Fe XXIV and Fe XXV are reported under the Iron Project. The transitions
include both the dipole allowed and intercombination obtained in
intermediate coupling including relativistic effects through the Breit Pauli
R-matrix method (BPRM) in the close coupling approximation.
Both the energies and the transition
probabilities agree generally to within with nearly all of the
most accurate calculated and measured values available.
It might be concluded that for highly charged ions the
relativistic and QED effects omitted from consideration in the
BPRM calculations should lead to an error not exceeding the
estimated uncertainty. However, much more work needs to be done to
investigate the precise magnitude of the various effects on
increasingly complex atomic systems. Calculations are presently
under way for Fe V and Fe XVI.
We should expect the present data to be particularly useful in the analysis of
X-ray and Extreme Ultraviolet spectra from astrophysical and laboratory
sources where non-local thermodynamic equilibrium (NLTE) atomic models with
many excited levels are needed.
Acknowledgements
This work was partially supported by U.S. National Science Foundation (AST-9870089) and the NASA ADP program. We should like to thank Dr. Gordon Drake and Dr. Ulyana Safronova for communications. The computational work was carried out on the vector machine Cray T94 at the Ohio Supercomputer Center in Columbus, Ohio.
Copyright The European Southern Observatory (ESO)