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Reanalysis of neutron-capture elements in the benchmark r-rich star CS 31082-001

Ernandes, H. LU ; Castro, M. J. ; Barbuy, B. ; Spite, M. ; Hill, V. ; Castilho, B. and Evans, C. J. (2023) In Monthly Notices of the Royal Astronomical Society 524(1). p.656-677
Abstract

We revisit the abundances of neutron-capture elements in the metal-poor ([Fe/H] = -2.9) r-process-rich halo star CS 31082-001. Partly motivated by the development of the new near-ultraviolet Cassegrain U-band Efficient Spectrograph for the Very Large Telescope, we compiled an expanded line list for heavy elements over the range 3000-4000 Å, including hyperfine structure for several elements. Combining archival near-ultraviolet spectra of CS 31082-001 from the Hubble Space Telescope and the Very Large Telescope, we investigate the abundances and nucleosynthesis of 35 heavy elements (Ge, Sr, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Sn, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Os, Ir, Pt, Pb, Bi, Th, and U). Our analysis... (More)

We revisit the abundances of neutron-capture elements in the metal-poor ([Fe/H] = -2.9) r-process-rich halo star CS 31082-001. Partly motivated by the development of the new near-ultraviolet Cassegrain U-band Efficient Spectrograph for the Very Large Telescope, we compiled an expanded line list for heavy elements over the range 3000-4000 Å, including hyperfine structure for several elements. Combining archival near-ultraviolet spectra of CS 31082-001 from the Hubble Space Telescope and the Very Large Telescope, we investigate the abundances and nucleosynthesis of 35 heavy elements (Ge, Sr, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Sn, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Os, Ir, Pt, Pb, Bi, Th, and U). Our analysis includes the first abundance estimates for tin, holmium, and ytterbium from these data, and the first for lutetium from ground-based data, enabling a more complete view of the abundance pattern of this important reference star. In general, the r-process-dominated elements are as enhanced as those in the Sun, particularly for elements with Z ≥ 56 (Ba and heavier). However, the abundances for the lighter elements in our sample, from Ge to Sn (31 ≤ Z ≤ 50), do not scale with the solar abundance pattern. Moreover, the Ge abundance is deficient relative to solar, indicating that it is dominantly an iron-peak rather than neutron-capture element. Our results (or upper limits) on Sn, Pt, Au, Pb, and Bi all pose further questions, prompting further study on the origin and evolution of the known r-rich and actinide-rich, metal-poor stars.

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author
; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Galaxy: halo, stars: abundances, stars: atmospheres, stars: individual: BPS CS 31082-001
in
Monthly Notices of the Royal Astronomical Society
volume
524
issue
1
pages
22 pages
publisher
Oxford University Press
external identifiers
  • scopus:85166061090
ISSN
0035-8711
DOI
10.1093/mnras/stad1764
language
English
LU publication?
yes
id
5cbaea58-f0d1-4875-8381-58de5aeb2fc4
date added to LUP
2023-10-24 14:52:48
date last changed
2024-04-19 02:50:58
@article{5cbaea58-f0d1-4875-8381-58de5aeb2fc4,
  abstract     = {{<p>We revisit the abundances of neutron-capture elements in the metal-poor ([Fe/H] = -2.9) r-process-rich halo star CS 31082-001. Partly motivated by the development of the new near-ultraviolet Cassegrain U-band Efficient Spectrograph for the Very Large Telescope, we compiled an expanded line list for heavy elements over the range 3000-4000 Å, including hyperfine structure for several elements. Combining archival near-ultraviolet spectra of CS 31082-001 from the Hubble Space Telescope and the Very Large Telescope, we investigate the abundances and nucleosynthesis of 35 heavy elements (Ge, Sr, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Sn, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Os, Ir, Pt, Pb, Bi, Th, and U). Our analysis includes the first abundance estimates for tin, holmium, and ytterbium from these data, and the first for lutetium from ground-based data, enabling a more complete view of the abundance pattern of this important reference star. In general, the r-process-dominated elements are as enhanced as those in the Sun, particularly for elements with Z ≥ 56 (Ba and heavier). However, the abundances for the lighter elements in our sample, from Ge to Sn (31 ≤ Z ≤ 50), do not scale with the solar abundance pattern. Moreover, the Ge abundance is deficient relative to solar, indicating that it is dominantly an iron-peak rather than neutron-capture element. Our results (or upper limits) on Sn, Pt, Au, Pb, and Bi all pose further questions, prompting further study on the origin and evolution of the known r-rich and actinide-rich, metal-poor stars.</p>}},
  author       = {{Ernandes, H. and Castro, M. J. and Barbuy, B. and Spite, M. and Hill, V. and Castilho, B. and Evans, C. J.}},
  issn         = {{0035-8711}},
  keywords     = {{Galaxy: halo; stars: abundances; stars: atmospheres; stars: individual: BPS CS 31082-001}},
  language     = {{eng}},
  month        = {{09}},
  number       = {{1}},
  pages        = {{656--677}},
  publisher    = {{Oxford University Press}},
  series       = {{Monthly Notices of the Royal Astronomical Society}},
  title        = {{Reanalysis of neutron-capture elements in the benchmark r-rich star CS 31082-001}},
  url          = {{http://dx.doi.org/10.1093/mnras/stad1764}},
  doi          = {{10.1093/mnras/stad1764}},
  volume       = {{524}},
  year         = {{2023}},
}