Context. We present a theoretical investigation of dielectronic recombination (DR) of Ar-like ions that sheds new light on the behavior of the rate coefficient at low-temperatures where these ions form in photoionized plasmas.
Aims: We provide results for the total and partial Maxwellian-averaged DR rate coefficients from the initial ground level of K ii-Zn xiii ions. It is expected that these new results will advance the accuracy of the ionization balance for Ar-like M-shell ions and pave the way towards a detailed modeling of astrophysically relevant X-ray absorption features.
Methods: We utilize the AUTOSTRUCTURE computer code to obtain the accurate core-excitation thresholds in target ions and carry out multiconfiguration Breit-Pauli (MCBP) calculations of the DR cross section in the independent-processes, isolated-resonance, distorted-wave (IPIRDW) approximation.
Results: Our results mediate the complete absence of direct DR calculations for certain Ar-like ions and question the reliability of the existing empirical rate formulas, often inferred from renormalized data within this isoelectronic sequence.
Astronomy and Astrophysics
- Pub Date:
- June 2010
- atomic data;
- atomic processes;
- Physics - Atomic Physics;
- Physics - Plasma Physics;
- Physics - Space Physics