First stars XVI. HST/STIS abundances of heavy elements in the uranium-rich metal-poor star CS 31082-001

C. Siquerira Mello Jr.; M. Spite; B. Barbuy; F. Spite; E. Caffau; V. Hill; S. Wanajo; F. Primas; B. Plez; R. Cayrel; Birgitta Nordström; Johannes Andersen; C. Sneden; T.C. Beers; P. Bonifacio; P. Francois; P. Molaro

First stars XVI. HST/STIS abundances of heavy elements in the uranium-rich metal-poor star CS 31082-001

C. Siquerira Mello Jr., M. Spite, B. Barbuy, F. Spite, E. Caffau, V. Hill, S. Wanajo, F. Primas, B. Plez, R. Cayrel, Birgitta Nordström, Johannes Andersen, C. Sneden, T.C. Beers, P. Bonifacio, P. Francois, P. Molaro

Astrophysics and Planetary Science

45 Citations (Scopus)

Abstract

Context. The origin and site(s) of the r-process nucleosynthesis is(are) still not known with certainty, but complete, detailed r-element abundances offer our best clues. The few extremely metal-poor (EMP) stars with large r-element excesses allow us to study the r-process signatures in great detail, with minimal interference from later stages of Galactic evolution. CS 31082-001 is an outstanding example of the information that can be gathered from these exceptional stars. Aims. Here we aim to complement our previous abundance determinations for third-peak r-process elements with new and improved results for elements of the first and second r-process peaks from near-UV HST/STIS and optical UVES spectra. These results should provide new insight into the nucleosynthesis of the elements beyond iron. Methods. The spectra were analyzed by a consistent approach based on an OSMARCS LTE model atmosphere and the Turbospectrum spectrum synthesis code to derive abundances of heavy elements in CS 31082-001, and using updated oscillator strengths from the recent literature. Synthetic spectra were computed for all lines of the elements of interest to check for proper line intensities and possible blends in these crowded spectra. Our new abundances were combined with the best previous results to provide reliable mean abundances for the first and second-peak r-process elements. Results. We present new abundances for 23 neutron-capture elements, 6 of which Ge, Mo, Lu, Ta, W, and Re have not been reported before. This makes CS 31082-001 the most completely studied r-II star, with abundances for a total of 37 neutron-capture elements. We also present the first NLTE+3D abundance of lead in this star, further constraining the nature of the r-process.

Original language	English
Article number	A122
Journal	Astronomy & Astrophysics
Volume	550
Number of pages	17
ISSN	0004-6361
Publication status	Published - 1 Feb 2013

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http://dx.doi.org/10.1051/0004-6361/201219949

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Siquerira Mello Jr., C., Spite, M., Barbuy, B., Spite, F., Caffau, E., Hill, V., Wanajo, S., Primas, F., Plez, B., Cayrel, R., Nordström, B., Andersen, J., Sneden, C., Beers, T. C., Bonifacio, P., Francois, P., & Molaro, P. (2013). First stars XVI. HST/STIS abundances of heavy elements in the uranium-rich metal-poor star CS 31082-001. Astronomy & Astrophysics, 550, Article A122. http://dx.doi.org/10.1051/0004-6361/201219949

Siquerira Mello Jr., C, Spite, M, Barbuy, B, Spite, F, Caffau, E, Hill, V, Wanajo, S, Primas, F, Plez, B, Cayrel, R, Nordström, B, Andersen, J, Sneden, C, Beers, TC, Bonifacio, P, Francois, P & Molaro, P 2013, 'First stars XVI. HST/STIS abundances of heavy elements in the uranium-rich metal-poor star CS 31082-001', Astronomy & Astrophysics, vol. 550, A122. <http://dx.doi.org/10.1051/0004-6361/201219949>

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title = "First stars XVI. HST/STIS abundances of heavy elements in the uranium-rich metal-poor star CS 31082-001",

abstract = "Context. The origin and site(s) of the r-process nucleosynthesis is(are) still not known with certainty, but complete, detailed r-element abundances offer our best clues. The few extremely metal-poor (EMP) stars with large r-element excesses allow us to study the r-process signatures in great detail, with minimal interference from later stages of Galactic evolution. CS 31082-001 is an outstanding example of the information that can be gathered from these exceptional stars. Aims. Here we aim to complement our previous abundance determinations for third-peak r-process elements with new and improved results for elements of the first and second r-process peaks from near-UV HST/STIS and optical UVES spectra. These results should provide new insight into the nucleosynthesis of the elements beyond iron. Methods. The spectra were analyzed by a consistent approach based on an OSMARCS LTE model atmosphere and the Turbospectrum spectrum synthesis code to derive abundances of heavy elements in CS 31082-001, and using updated oscillator strengths from the recent literature. Synthetic spectra were computed for all lines of the elements of interest to check for proper line intensities and possible blends in these crowded spectra. Our new abundances were combined with the best previous results to provide reliable mean abundances for the first and second-peak r-process elements. Results. We present new abundances for 23 neutron-capture elements, 6 of which Ge, Mo, Lu, Ta, W, and Re have not been reported before. This makes CS 31082-001 the most completely studied r-II star, with abundances for a total of 37 neutron-capture elements. We also present the first NLTE+3D abundance of lead in this star, further constraining the nature of the r-process.",

author = "{Siquerira Mello Jr.}, C. and M. Spite and B. Barbuy and F. Spite and E. Caffau and V. Hill and S. Wanajo and F. Primas and B. Plez and R. Cayrel and Birgitta Nordstr{\"o}m and Johannes Andersen and C. Sneden and T.C. Beers and P. Bonifacio and P. Francois and P. Molaro",

year = "2013",

month = feb,

day = "1",

language = "English",

volume = "550",

journal = "Astronomy & Astrophysics",

issn = "0004-6361",

publisher = "E D P Sciences",

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TY - JOUR

T1 - First stars XVI. HST/STIS abundances of heavy elements in the uranium-rich metal-poor star CS 31082-001

AU - Siquerira Mello Jr., C.

AU - Spite, M.

AU - Barbuy, B.

AU - Spite, F.

AU - Caffau, E.

AU - Hill, V.

AU - Wanajo, S.

AU - Primas, F.

AU - Plez, B.

AU - Cayrel, R.

AU - Nordström, Birgitta

AU - Andersen, Johannes

AU - Sneden, C.

AU - Beers, T.C.

AU - Bonifacio, P.

AU - Francois, P.

AU - Molaro, P.

PY - 2013/2/1

Y1 - 2013/2/1

N2 - Context. The origin and site(s) of the r-process nucleosynthesis is(are) still not known with certainty, but complete, detailed r-element abundances offer our best clues. The few extremely metal-poor (EMP) stars with large r-element excesses allow us to study the r-process signatures in great detail, with minimal interference from later stages of Galactic evolution. CS 31082-001 is an outstanding example of the information that can be gathered from these exceptional stars. Aims. Here we aim to complement our previous abundance determinations for third-peak r-process elements with new and improved results for elements of the first and second r-process peaks from near-UV HST/STIS and optical UVES spectra. These results should provide new insight into the nucleosynthesis of the elements beyond iron. Methods. The spectra were analyzed by a consistent approach based on an OSMARCS LTE model atmosphere and the Turbospectrum spectrum synthesis code to derive abundances of heavy elements in CS 31082-001, and using updated oscillator strengths from the recent literature. Synthetic spectra were computed for all lines of the elements of interest to check for proper line intensities and possible blends in these crowded spectra. Our new abundances were combined with the best previous results to provide reliable mean abundances for the first and second-peak r-process elements. Results. We present new abundances for 23 neutron-capture elements, 6 of which Ge, Mo, Lu, Ta, W, and Re have not been reported before. This makes CS 31082-001 the most completely studied r-II star, with abundances for a total of 37 neutron-capture elements. We also present the first NLTE+3D abundance of lead in this star, further constraining the nature of the r-process.

AB - Context. The origin and site(s) of the r-process nucleosynthesis is(are) still not known with certainty, but complete, detailed r-element abundances offer our best clues. The few extremely metal-poor (EMP) stars with large r-element excesses allow us to study the r-process signatures in great detail, with minimal interference from later stages of Galactic evolution. CS 31082-001 is an outstanding example of the information that can be gathered from these exceptional stars. Aims. Here we aim to complement our previous abundance determinations for third-peak r-process elements with new and improved results for elements of the first and second r-process peaks from near-UV HST/STIS and optical UVES spectra. These results should provide new insight into the nucleosynthesis of the elements beyond iron. Methods. The spectra were analyzed by a consistent approach based on an OSMARCS LTE model atmosphere and the Turbospectrum spectrum synthesis code to derive abundances of heavy elements in CS 31082-001, and using updated oscillator strengths from the recent literature. Synthetic spectra were computed for all lines of the elements of interest to check for proper line intensities and possible blends in these crowded spectra. Our new abundances were combined with the best previous results to provide reliable mean abundances for the first and second-peak r-process elements. Results. We present new abundances for 23 neutron-capture elements, 6 of which Ge, Mo, Lu, Ta, W, and Re have not been reported before. This makes CS 31082-001 the most completely studied r-II star, with abundances for a total of 37 neutron-capture elements. We also present the first NLTE+3D abundance of lead in this star, further constraining the nature of the r-process.

M3 - Journal article

SN - 0004-6361

VL - 550

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

M1 - A122

ER -

First stars XVI. HST/STIS abundances of heavy elements in the uranium-rich metal-poor star CS 31082-001

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