Open AccessPhotoionization and recombination of Fe xix
Author(s) -
Zhang Hong Lin,
Pradhan Anil K.
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03173.x
Subject(s) - physics , photoionization , recombination rate , atomic physics , recombination , relativistic quantum chemistry , wave function , ground state , resonance (particle physics) , pauli exclusion principle , configuration interaction , coupling (piping) , ionization , ion , quantum mechanics , excited state , gene , mechanical engineering , biochemistry , chemistry , engineering
Photoionization cross‐sections and recombination rate coefficients are presented for the L‐shell ground‐state fine‐structure levels 2s 2 2p 4 3 P 2,0,1 of Fe xix . Several sets of calculations including relativistic effects are carried out: (i) Breit–Pauli R ‐matrix (BPRM), (ii) relativistic distorted‐wave (RDW), and (iii) a semirelativistic calculation. Non‐relativistic LS ‐coupling calculations are also performed for comparison. The BPRM calculations employ a configuration‐interaction target representation for Fe xx consisting of 12 LS terms (23 fine‐structure levels), as in the recently reported BPRM calculations by Donnelly et al. The background cross‐sections in all three sets of present calculations agree with one another, but differ considerably from those of Donnelly et al. Owing to much more extensive resonance structures in the present BPRM calculations, the sum of the corresponding recombination rate coefficients for the 3 P 2,0,1 levels is up to 50 per cent higher than the LS rates at low temperatures but comparable for higher temperatures; this is in contrast to the results of Donnelly et al. who obtained the LS rates to be higher than their BPRM results by about a factor of 2. Reasons for these discrepancies are discussed.