Радиационные константы в спектре иона W VII

Radiative transition probabilities 4f135p66p + 4f145p56p - 4f136s, 4f137s, and 4f137s levels lifetimes for erbium-like W VII were calculated smiempirically in intermediate coupling scheme using experimental energy levels. Radial transition integrals were derived in length form with Hartree-Fock functions.

Вероятности радиационных переходов в спектрах никелеподобных ионов Cd XXI, In XXII, Sn XXIII

Probabilities of electric-dipole 3 d ^94 p → 3 d ^10, 3 d ^94 s transitions in the spectra of nickel-like ions Cd XXI, In XXII, and Sn XXIII are calculated semiempirically in the intermediate coupling scheme. The radial integrals necessary for obtaining absolute values of the probabilities are calculated in the length form with Hartree–Fock functions.

Plasma diagnostics for planetary nebulae and H ii regions using N ii and O ii optical recombination lines

We carry out plasma diagnostic analysis for a number of planetary nebulae (PNe) and H ii regions. We use N ii and O ii optical recombination lines (ORLs) with new effective recombination coefficients calculated under the intermediate coupling scheme, for a range of electron temperatures (Te) and densities (Ne), and fitted against the most reliable measurements. Comparing Te derived from ORLs, collisionally excited lines (CELs), the hydrogen Balmer Jump, and/or He i if available, we find the relation Te (ORLs) < Te (He i) < Te (H i BJ) < Te (CELs), confirming the physical conditions in the bi-abundance model postulated by Liu et al., i.e. the nebula contains another cold, metal-rich and probably H-deficient component.

Very deep spectroscopy of the bright Saturn nebula NGC 7009: The optical recombination spectrum and new effective recombination coefficients

We present very deep spectroscopic observations of the rich optical recombination line (ORL) spectrum of the bright Saturn nebula NGC 7009. Detailed spectral analyses, combined with systematic emission line identifications, in the whole optical range (3040–11 000 Å) give more than 1000 emission lines, over 80% of which are ORLs. New calculations of the N ii effective recombination coefficients in intermediate coupling scheme are carried out. These N ii atomic data, together with the most recent O ii and Ne ii effective recombination coefficients, are utilized in the spectral analyses of NGC 7009. Departure from LS coupling is noticed. Agreement is found between the observed and predicted relative intensities of ORLs. The elemental abundances of C, N, O, and Ne deduced from ORLs are systematically higher than those from collisionally excited lines (CELs) by a factor of 5–7.

Effective collision strengths for electron-impact excitation of Al10+

Electron collision strengths for electron-impact excitation of Li-like and Al ion are evaluated in close-coupling approximation using the multi-channel R-matrix method. Five LS target eigenstates are included in the expansion of the total wave function, consisting of the twon= 2 states withconfigurationsof 1s22s, 1s22p, and threen= 3 states withconfigurations1s23s, 1s23p, and 1s23d. Collision strengths are obtained in LS coupling using FARM code and in intermediate coupling scheme using the SUPERSTRUCTURE program. The effective collision strengths are calculated as function of temperature, up to a temperature that does not exceed half of the maximum energy in the R-matrix run.

Allowed and Forbidden n = 2?2 Transitions of the Elements Kr and Mo

Relativistic intermediate-coupling wavefunctions are used to evaluate transition energies, line strengths and transition probabilities for all allowed and forbidden n = 2-2 transitions for krypton and molybdenum beryllium-like ions. Our results are in very good agreement with those calculated using the relativistic multi-configuration Hartree-Fock approximation. These calculations were carried out under the same physical assumption that the dominant correlation effect is the n = 2 intra-shell correlation. We also discuss the importance of relativistic effects on the radial functions, the relativistic intermediate-coupling scheme in the variational process, the importance of radiative corrections for transition energies between states with different occupation of the 2s shell, and the relative importance of intra- versus inter-shell correlation effects.