Electron‐Ion Recombination Rate Coefficients and Photoionization Cross Sections for Astrophysically Abundant Elements. XI. N v – vi and F vii – viii for Ultraviolet and X‐Ray Modeling

The inverse processes of photoionization and electron-ion recombination for h þ N v$ N viþ e, h þ N vi$ N viiþ e, h þ F vii$ F viiiþ e ,a ndh þ F viii$ F ixþ e are studied in detail using a self-consistent unified method for the total electron-ion recombination. The method enables calculation of the total and level- specificrecombinationratecoefficientsRandR(i),subsumingbothradiativeanddielectronicrecombination(RR and DR). The photoionization and recombination cross sectionsPI andRC are computed using an identical wave function expansion for both processes in the close coupling approximation using the R-matrix method. The results include total and partial photoionization cross sections and recombination rate coefficients for all fine-structure levelsupton 10, about 100 forLi-like Nvand Fviiwith 1/2 J 17/2, and over 170 for He-like Nvi and Fviii with 0 J 10. Level-specificPI(nSLJ )a ndR(T; nSLJ) are calculated for the first time for these ions. The coupled-channelwavefunctionexpansionsforNvandFviiconsistof17levelsofcoresNviandFviii,respectively, and for N vi and F viii consist of 16 levels of cores N vii and F ix, respectively. Relativistic fine structure is con- sidered through the Breit-Pauli R-matrix method. The single-valued totalR(T) is presented over an extended tem- perature range for astrophysical and laboratory plasma applications. Although the total unifiedR(T) for all ions agree well with the available published RR+DR rates, significant differences are noted at the DR peak forNv .T otal RC(E )a ndR(E) as functions of photoelectron energy are presented for comparison with experiments. Total rates for H-like N vii and F ix are also given for completeness. The cross sectionsPI andRC include important atomic effects such as radiation damping, channel couplings, and interference of DR and RR, and should be accurate to within 10%-15%. The comprehensive data sets are applicable for ionization balance and recombination-cascade models for UVand X-ray lines. Subject headingg atomic data — atomic processes — line: formation — X-rays: general