uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
The Hamburg/ESO R-process Enhanced Star survey (HERES)
Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France..
Heidelberg Univ, Zentrum Astron, Konigstuhl 12, D-69117 Heidelberg, Germany..
Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA.;Univ Notre Dame, JINA Ctr Evolut Elements, Notre Dame, IN 46556 USA..
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Theoretical Astrophysics.
Show others and affiliations
2017 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 607, article id A91Article in journal (Refereed) Published
Abstract [en]

We report an abundance analysis for the highly r-process-enhanced (r-II) star CS 29497-004, a very metal-poor giant with solar system T-eff = 5013 K and [Fe/H] = -2 : 85, whose nature was initially discovered in the course of the HERES project. Our analysis is based on high signal-to-noise ratio, high-resolution (R similar to 75 000) VLT/UVES spectra and MARCS model atmospheres under the assumption of local thermodynamic equilibrium, and obtains abundance measurements for a total of 46 elements, 31 of which are neutron-capture elements. As is the case for the other similar to 25 r-II stars currently known, the heavy-element abundance pattern of CS 29497-004 well-matches a scaled solar system second peak r-process-element abundance pattern. We confirm our previous detection of Th, and demonstrate that this star does not exhibit an "actinide boost". Uranium is also detected (log is an element of (U) = -2 : 20 +/- 0 : 30), albeit with a large measurement error that hampers its use as a precision cosmo-chronometer. Combining the various elemental chronometer pairs that are available for this star, we derive a mean age of 12 : 2 +/- 3 : 7 Gyr using the theoretical production ratios from published waitingpoint approximation models. We further explore the high-entropy wind model (Farouqi et al. 2010, ApJ, 712, 1359) production ratios arising from different neutron richness of the ejecta (Y-e), and derive an age of 13 : 7 +/- 4 : 4 Gyr for a best-fitting Y-e = 0 : 447. The U/Th nuclei-chronometer is confirmed to be the most resilient to theoretical production ratios and yields an age of 16 : 5 +/- 6 : 6 Gyr. Lead (Pb) is also tentatively detected in CS 29497-004, at a level compatible with a scaled solar r-process, or with the theoretical expectations for a pure r-process in this star.

Place, publisher, year, edition, pages
EDP SCIENCES S A , 2017. Vol. 607, article id A91
Keywords [en]
stars: abundances, stars: individual: CS 29497-004, stars: Population II, stars: chemically peculiar, Galaxy: halo
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
URN: urn:nbn:se:uu:diva-356350DOI: 10.1051/0004-6361/201629092ISI: 000415863500002OAI: oai:DiVA.org:uu-356350DiVA, id: diva2:1235251
Funder
German Research Foundation (DFG), Sonderforschungsbereich SFB 881Knut and Alice Wallenberg FoundationAvailable from: 2018-07-24 Created: 2018-07-24 Last updated: 2018-07-24Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Authority records BETA

Barklem, Paul S.

Search in DiVA

By author/editor
Barklem, Paul S.
By organisation
Theoretical Astrophysics
In the same journal
Astronomy and Astrophysics
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 6 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf