On the interpretation of complex atomic spectra by means of the parametric Racah–Slater method and Cowan codes1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

2011 ◽  
Vol 89 (4) ◽  
pp. 451-456 ◽  
Author(s):  
Jean-François Wyart

Theoretical studies of electronic configurations of several lanthanide ions in the Racah–Slater approach were performed with the standard suite of codes by R.D. Cowan, including a fitting of energy parameters. Configuration interaction was considered explicitly in the low configurations and was processed by effective parameters for doubly-excited far configurations. Mean errors lower than 100 cm–1 were obtained. Systematic differences are noticed between radial integrals calculated by ab initio PHFR and the Pfit fitted values. The consistency of the scaling factors SF(P) = Pfit/PHFR and of the effective parameters for far configuration effects is shown. In an application to Tm II, the predicted transition probabilities compared well with line intensities and led to the finding of new energy levels. In Nd II, the configuration 4f5 is identified.

2011 ◽  
Vol 89 (4) ◽  
pp. 417-428 ◽  
Author(s):  
Robert L. Kurucz

I present a progress report on including all the lines in the line lists, including all the lines in the opacities, and including all the lines in the model atmosphere and spectrum synthesis calculations. The increased opacity will improve stellar atmosphere, pulsation, stellar interior, asteroseismology, nova, supernova, and other radiation-hydrodynamics calculations. I also report on producing high-resolution, high-signal-to-noise atlases for use in verifying the line data and spectrum calculations, and as tools for extending laboratory spectrum analyses to higher energy levels. All the data are available on my web site: kurucz.harvard.edu .


2011 ◽  
Vol 89 (4) ◽  
pp. 361-369
Author(s):  
Keith A. Olive

In many theories of unified interactions, there are additional degrees of freedom that may allow for the variation of the fundamental constants of nature. I will review the motivation for and theoretical relations between such variations. I will then review the various astrophysical and experimental constraints on the variations of constants and their dependence on spectroscopic data.


2014 ◽  
Vol 92 (11) ◽  
pp. 1285-1296 ◽  
Author(s):  
Sunny Aggarwal ◽  
Nupur Verma ◽  
A.K. Singh ◽  
Narendra Singh ◽  
Rinku Sharma ◽  
...  

We present accurate atomic structure calculations for the lowest 200 fine structural energy levels for oxygen-like nickel, which may be a useful ion for both astrophysical and fusion plasmas. For the calculations of energy levels and radiative rates, we have used the multiconfigurational Dirac–Fock method. Our results are compared with those obtained using other numerical methods and experiments so that their accuracy can be assessed. The transition wavelengths, oscillator strengths, and radiative rates are reported for electric dipole (E1) transitions from the ground state. We have also presented the transition probabilities and transition wavelength of some forbidden transitions. Finally, we predict new energy levels, oscillator strengths, and transition probability data, where no other theoretical or experimental results are available, which may be useful for future experimental work.


2011 ◽  
Vol 89 (5) ◽  
pp. 551-570 ◽  
Author(s):  
A. Kramida

This contribution reviews experimental and theoretical work on spectroscopy of tungsten published since the last critical compilation of the energy levels and spectral lines of highly ionized tungsten (Kramida and Shirai. At. Data Nucl. Data Tables, 95, 305 (2009)). Since then, 18 new experimental studies were published, which resulted in new identifications and (or) significantly improved wavelengths of spectral lines and energy levels of Li-like through As-like and Pm-like tungsten. A few tens of theoretical studies of tungsten spectra were published since 2008. A number of them report on high-precision calculations of energy levels, transition wavelengths, and radiative rates for tungsten spectra, such as neutral tungsten, Yb-like, Rh-like through Rb-like, Ag-like, Ga-like, Zn-like, Ni-like, Ca-like, Al-like, Mg-like, Na-like, Ne-like, B-like, Be-like, and Li-like. These developments are reviewed. Based on new experimental data, systematic errors are removed from some of the earlier measurements. Some new data are obtained by analyzing publications of other authors. Based on new published theoretical data, some old experimental results were confirmed and assessed. Revised and extended tables of energy levels and spectral lines of highly ionized tungsten are presented.


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