scholarly journals Recombination Spectra of Planetary Nebulae

1983 ◽  
Vol 103 ◽  
pp. 514-516
Author(s):  
P.O. Bogdanovich ◽  
Z.B. Rudzikas ◽  
T. H. Feklistova ◽  
A.F. Kholtygin ◽  
A.A. Nikitin ◽  
...  
Keyword(s):  
Transition Probabilities ◽  
Planetary Nebulae ◽  
Dielectronic Recombination ◽  
Wave Functions ◽  
Energy Spectra ◽  
Coupling Scheme ◽  
Intermediate Coupling ◽  
Hartree Fock ◽  
Radiative Transitions ◽  
Intermediate Coupling Scheme

The lines of the transitions between the subordinate levels of the CIII, NIII etc. ions are observed in the spectra of planetary nebulae (PN) (1). Their theoretical intensities may be found by solving the stationarity equations and accounting for both the recombination and cascade radiative transitions. It is possible to calculate the recombination spectra in various approaches: the single- or multi-configuration approximations (SCA and MCA) making use of both the superposition of configurations (SC) or the multiconfigurational Hartree-Fock-Jucys equations (2), taking into consideration the contribution of the dielectronic recombination to the intensities of the recombination lines. The energy spectra, the transition probabilities etc., as a rule ought to be calculated in the intermediate coupling scheme (2). Both analytical or numerical (e.g. Hartree-Fock) wave functions may be adopted.

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

1984 ◽  
Vol 37 (6) ◽  
pp. 601
Author(s):  
R Glass
Keyword(s):  
Transition Probabilities ◽  
Relativistic Effects ◽  
Correlation Effect ◽  
Coupling Scheme ◽  
Intermediate Coupling ◽  
Transition Energies ◽  
Hartree Fock ◽  
Physical Assumption ◽  
Variational Process ◽  
Intermediate Coupling Scheme

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.

scholarly journals Радиационные константы в спектре иона W VII

2020 ◽  
Vol 128 (8) ◽  
pp. 1074
Author(s):  
А.В. Логинов ◽  
В.И. Никитченко
Keyword(s):  
Transition Probabilities ◽  
Energy Levels ◽  
Radiative Transition ◽  
Coupling Scheme ◽  
Intermediate Coupling ◽  
Hartree Fock ◽  
Experimental Energy ◽  
Intermediate Coupling Scheme

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.

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

2011 ◽  
Vol 7 (S283) ◽  
pp. 432-433
Author(s):  
Ian A. McNabb ◽  
Xuan Fang ◽  
Xiao–Wei Liu ◽  
Peter J. Storey
Keyword(s):  
Plasma Diagnostics ◽  
Planetary Nebulae ◽  
Coupling Scheme ◽  
H Ii Regions ◽  
Diagnostic Analysis ◽  
Plasma Diagnostic ◽  
Intermediate Coupling ◽  
Physical Conditions ◽  
Cold Metal ◽  
Intermediate Coupling Scheme

AbstractWe 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.

Relativistic oscillator strengths for np2 → np(n + 1)s transition array of SnI and PbI spectra in jj and intermediate coupling

1979 ◽  
Vol 57 (2) ◽  
pp. 147-151 ◽  
Author(s):  
J. Migdałek
Keyword(s):  
Transition Probabilities ◽  
Theoretical Data ◽  
Wave Functions ◽  
Oscillator Strengths ◽  
Intermediate Coupling ◽  
Hartree Fock ◽  
Semiempirical Approach ◽  
Exchange Effects ◽  
Relativistic Oscillator ◽  
Transition Array

The relativistic oscillator strengths for the np2 → np(n + 1)s transition array as well as the lifetimes of levels of the np(n + 1)s configuration in SnI and PbI spectra were calculated in jj and intermediate coupling. The relativistic radial integrals were computed employing the wave functions obtained by a semiempirical approach which allowed for exchange effects. The results obtained are compared with existing experimental and theoretical data. The significance of intermediate coupling for oscillator strengths computations is discussed. The agreement with experiment is for the present semiempirical results generally better (particularly for the PbI spectrum) than for oscillator strength deduced from 'Optimized Hartree–Fock–Slater' transition probabilities, which were published previously.

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

2019 ◽  
Vol 126 (2) ◽  
pp. 118
Author(s):  
А.В. Логинов
Keyword(s):  
Electric Dipole ◽  
Coupling Scheme ◽  
Intermediate Coupling ◽  
Hartree Fock ◽  
Intermediate Coupling Scheme

AbstractProbabilities 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.

scholarly journals Intensities in Complex Spectra of Highly Ionized Atoms

1984 ◽  
Vol 86 ◽  
pp. 44-44
Author(s):  
M. Klapisch ◽  
A. Bar-Shalom ◽  
A. Cohen
Keyword(s):  
Cross Sections ◽  
Wave Functions ◽  
Coupling Scheme ◽  
Distorted Wave ◽  
Intermediate Coupling ◽  
Potential Wave ◽  
Excitation Cross Sections ◽  
Collisional Radiative Model ◽  
Radiative Model ◽  
Efficient Program

We describe a package of programs for the implementation of the collisional-radiative model to complex configurations. The number of levels taken into account may be several hundreds. The heart of the package is a very efficient program for excitation cross sections in the Distorted Wave framework, using the Relativistic Parametric Potential wave functions. The basic jj coupling scheme actually simplified the computations, enabling a useful factorization into radial and angular parts. Intermediate coupling and configuration interactions are accounted for. We computed ratios of intensities of 3d9 − 3d84s (E2) to 3d9 −3d84p (El) transitions as functions of ne and Te in Xe XXVIII and other Co-like spectra. The atomic model involves all the levels of configurations (3p6)3d9; −3d84s, −3d84p, −3d84d, −3d84f, and (3p5) −3d10, −3d94p. (275 levels) and all the transitions between them. Results compare very well with experimental spectra from TFR.

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