Astronomy and Astrophysics – Astrophysics
Scientific paper
Aug 1999
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1999mnras.307..595d&link_type=abstract
Monthly Notices, Volume 307, Issue 3, pp. 595-604.
Astronomy and Astrophysics
Astrophysics
5
Scientific paper
High-quality atomic data concerning the interaction of photons with highly ionized ions of iron are an essential requirement in the modelling of X-ray emission from astrophysical plasmas. Consequently a detailed study of the photoionization of the ground-state fine-structure levels (2s^22p^4 ^3P_2,0,1) of FeXIX has been undertaken, and a set of high-resolution cross-sections for photoionization of each of these levels obtained. We have considered both the total and partial cross-section cases, with the latter restricted to those instances where the residual ion is left in one of the energetically lowest 23 Jpi (12 LSpi) states of FeXX. The calculation was performed by applying the Breit-Pauli R-matrix codes using a sophisticated representation of these 23 target-states. This approach allows for the possibility of fine-structure splitting in both thresholds and resonances, as well as incorporating any coupling between target-states with different LS symmetries through the inclusion of the spin-orbit operator. A significant amount of such coupling is discovered in the present investigation, and is responsible for a background cross-section whose magnitude is lower than that determined in previous LS-coupling calculations by more than a factor of 2. Extensive resonance structure is also resolved, including shape resonances in the 133 -> 148Ryd photon energy region. Such structure has not been resolved in any previous investigation and is of extreme importance in the modelling of X-ray emission plasmas. Using the derived photoionization cross-section data, recombination rate coefficients are calculated using the Milne relation, for the case of an electron recombining with FeXX in the ground state to form FeXIX existing in each of the fine-structure ground-state levels. These recombination rates are summarized over a temperature range of 50 000 to 10^7K. To supplement these data further we also present a set of energy levels and oscillator strengths for FeXX.
Bell Kenneth L.
Donnelly David
Keenan Francis P.
No associations
LandOfFree
L-shell photoionization cross-sections for FeXIXXIX and FeXXXX recombination rate coefficients does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with L-shell photoionization cross-sections for FeXIXXIX and FeXXXX recombination rate coefficients, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and L-shell photoionization cross-sections for FeXIXXIX and FeXXXX recombination rate coefficients will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1269907