Special Issue on the 12th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas held at the Universidade de São Paulo on 4–7 July 2016 / Numéro spécial sur le 12e Colloque international sur les spectres atomiques et les forces d’oscillateur pour l’astrophysique et les plasmas en laboratoire qui s’est tenu à l’Université de São Paulo du 4 au 7 juillet 2016

2017 ◽  
Vol 95 (9) ◽  
pp. iii-iii
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.


2011 ◽  
Vol 89 (4) ◽  
pp. 429-437 ◽  
Author(s):  
W.R. Johnson

We give a brief outline of the theory of hyperfine quenching followed by a review of the progress that has been made in both theory and experiment since the pioneering work of Garstang (J. Opt. Soc. Am. 52, 845 (1962)).


2011 ◽  
Vol 89 (4) ◽  
pp. 403-412 ◽  
Author(s):  
Elmar Träbert ◽  
Yasuyuki Ishikawa ◽  
Juan A. Santana ◽  
Giulio Del Zanna

The structure of Si-like ions is discussed for the example of iron (spectrum Fe XIII). The 3s23p3d 3Fo term with its three fine structure levels of very different lifetimes has eluded the early observations. Meanwhile, complementary experimental techniques have permitted to track these levels. Theory has also evolved from approximate techniques to accurate ab initio calculations, the results of which cast doubt on some earlier Fe XIII line identifications and guide the search for and the identification of the correct lines in solar corona spectra.


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. 357-359
Author(s):  
B. Barbuy ◽  
C. Siqueira Mello ◽  
M. Spite ◽  
F. Spite ◽  
P. Bonifacio ◽  
...  

The abundance of heavy r-elements may provide a better understanding of the r-process, and the determination of several reference r-elements should allow a better determination of a star's age. The space UV region (λ < 3000 Å) presents a large number of lines of the heavy elements, and in the case of some elements, such as Bi, Pt, Au, detectable lines are not available elsewhere. The extreme “r-process star” CS 31082–001 ([Fe/H] = –2.9) was observed in the space UV to determine abundances of the heaviest stable elements, using STIS on board Hubble Space Telescope.


2011 ◽  
Vol 89 (5) ◽  
pp. 639-645 ◽  
Author(s):  
Elmar Träbert ◽  
Joel Clementson ◽  
Peter Beiersdorfer ◽  
Juan A. Santana ◽  
Yasuyuki Ishikawa

Previous observations of Zn-like ions of elements Yb (Z = 70) through U (Z = 92) in an electron beam ion trap differed (by value and by isoelectronic trend) from the (less precise) results of laser-produced plasma experiments and highlighted the need for much better calculations of ions with more than one electron in the valence shell. We review the progress since achieved and present new calculations for ions in the above range as well as EBIT observations of Zn-like Pt48+ ions (Z = 78). We identify accurate ab initio calculations that agree with the EBIT data as well as recent calculations that clearly fall short.


2011 ◽  
Vol 89 (5) ◽  
pp. 509-511 ◽  
Author(s):  
Peter Hakel

We report on a modeling study of the polarization properties of the Ly-α line in sulphur. The lower energy (J = 1/2) fine-structure component is unpolarized, while the polarization degree of the higher energy component (J = 3/2) can serve as a signature of an anisotropic electron distribution. We calculate the polarization degree of the J = 3/2 component with the help of a magnetic-sublevel population atomic kinetics model for plasma conditions that can arise in laser-produced plasma experiments. This demonstrates how observed polarization properties of the Ly-α could be connected with the characteristics of an anisotropic electron distribution.


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