IMPROVED LABORATORY TRANSITION PROBABILITIES FOR Ce ii, APPLICATION TO THE CERIUM ABUNDANCES OF THE SUN AND FIVE r-PROCESS-RICH, METAL-POOR STARS, AND RARE EARTH LAB DATA SUMMARY

By J. E. Lawler, C. Sneden, J. Cowan, I. Ivans, E. A. Den Hartog. 2009

139 citations recorded by the source corpus.

Recent radiative lifetime measurements accurate to ±5% using laser-induced fluorescence (LIF) on 43 even-parity and 15 odd-parity levels of Ce ii have been combined with new branching fractions measured using a Fourier transform spectrometer (FTS) to determine transition probabilities for 921 lines of Ce ii. This improved laboratory data set has been used to determine a new solar photospheric Ce abundance, log ε = 1.61 ± 0.01 (σ = 0.06 from 45 lines), a value in excellent agreement with the recommended meteoritic abundance, log ε = 1.61 ± 0.02. Revised Ce abundances have also been derived for the r-process-rich metal-poor giant stars BD+17°3248, CS 22892–052, CS 31082–001, HD 115444, and HD 221170. Between 26 and 40 lines were used for determining the Ce abundance in these five stars, yielding a small statistical uncertainty of ±0.01 dex similar to the solar result. The relative abundances in the metal-poor stars of Ce and Eu, a nearly pure r-process element in the Sun, matches r-process-only model predictions for solar system material. This consistent match with small scatter over a wide range of stellar metallicities lends support to these predictions of elemental fractions. A companion paper includes an interpretation of these new precision abundance results for Ce as well as new abundance results and interpretation for Pr, Dy, and Tm.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/118357d9c77e4ba4cb2347fe708fb6ab5841a98b

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In Astronomy and Astrophysics

1. B. Metzger
2. E. Berger
3. D. Kasen
4. C. Sneden
5. E. Quataert
6. Martin Asplund
7. J. Cowan
8. N. Grevesse

In Instrumentation

1. C. Sneden
2. M. Walker
3. J. Cowan
4. I. Ivans
5. Martin Asplund
6. I. Thompson
7. S. Shectman
8. J. E. Lawler

Citations in the corpus

• The elemental composition of the Sun - III. The heavy elements Cu to Th (2014, background): “…applied their very accurate atomic data to the determination of the solar abundances of all the rare Earth elements (La: Lawler et al. 2001a, Ce: Lawler et al. 2009, Nd: Den Hartog et al. 2003, Sm: Lawler et al. 2006, Eu: Lawler et al. 2001b, Gd: Den Hartog et al. 2006, Tb: Lawler et al. 2001c,…”
• THE ABUNDANCES OF NEUTRON-CAPTURE SPECIES IN THE VERY METAL-POOR GLOBULAR CLUSTER M15: A UNIFORM ANALYSIS OF RED GIANT BRANCH AND RED HORIZONTAL BRANCH STARS (2011, methodology): “Correspondingly, the extensive sets of rare earth gf -values from the Wisconsin Atomic Physics Group were adopted (Sneden et al. 2009(87), Lawler et al. 2009(62), and references therein).”
• DETAILED CHEMICAL ABUNDANCES IN THE r-PROCESS-RICH ULTRA-FAINT DWARF GALAXY RETICULUM 2 (2016, methodology): “…al. 1994; (19) Kramida et al. 2015, using HFS/IS from McWilliam 1998 when available; (20) Lawler et al. 2001a, using HFS from Ivans et al. 2006; (21) Lawler et al. 2009; (22) Li et al. 2007, using HFS from Sneden et al. 2009; (23) Ivarsson et al. 2001, using HFS from Sneden et al. 2009; (24) Den…”
• NEW RARE EARTH ELEMENT ABUNDANCE DISTRIBUTIONS FOR THE SUN AND FIVE r-PROCESS-RICH VERY METAL-POOR STARS (2009, methodology): “…& Sneden (2001a), Lawler et al. (2001b), Lawler et al. (2001c), Den Hartog et al. (2003), Lawler, Sneden, & Cowan (2004), Den Hartog et al. (2005), Lawler et al. (2006), Den Hartog et al. (2006), Lawler et al. (2007), Sobeck, Lawler, & Sneden (2007), Lawler et al. (2008b), and Lawler et al. (2009).”
• Electromagnetic counterparts of compact object mergers powered by the radioactive decay of r‐process nuclei (2010, background): “Most of the data available is experimental (e.g. Lawler et al. 2006, 2007, 2009; Biémont et al. 2007), since many body quantum mechanical calculations of these elements’ spectra represent a formidable task, even with modern computing.”
• The chemical composition of the Sun (2009, methodology): “In this context, we would like to particularly highlight the very careful laboratory measurements performed by the Wisconsin group (e.g. Lawler et al. 2009).”
• WHAT IS THE MOST PROMISING ELECTROMAGNETIC COUNTERPART OF A NEUTRON STAR BINARY MERGER? (2011, background): “…of kilonova spectra are unfortunately impossible because laboratory data on the spectral lines of r-process elements are currently sparse (e.g., Lawler et al. 2009); the closest known analog to a pure r-process photosphere are ultra metal-poor stars in the Galactic halo (e.g., Sneden et al.…”