The s-process at low metallicity

Richard J. Stancliffe, Maria A. Lugaro, Amanda I. Karakas, Carlos Rijs

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearch

Abstract

We present models for the slow neutron-capture process (s-process) in asymptotic giant branch stars of metallicity [Fe/H] = -2.3 and masses 0.9 - 6M. The models where the 13C burns radiatively (stars of around 2M) produce an overall good match to carbon-enhanced metalpoor (CEMP) stars showing barium enhancements (CEMP-s). On the other hand, none of our models can provide a match to the composition of CEMP stars showing both barium and europium enhancements (CEMP-s/r). The models fail to reproduce the observed Eu abundances, and they also fail to reproduce the correlation between the Eu and Ba abundances. They also cannot match the ratio of heavy-to-light s-process elements observed in many CEMP-s/r stars, which can be more than 10 times higher than in the Solar System. This work has been published [1] and the interested reader should refer to that work for further details, included published tables of yields.

Original languageEnglish
Title of host publicationFirst Stars IV - From Hayashi to the Future
Subtitle of host publicationKyoto, Japan; 21-25 May 2012
EditorsMasayuki Umemura, Kazuyuki Omukai
Place of PublicationUSA
PublisherAIP Publishing
Pages156-159
Number of pages4
ISBN (Print)9780735410923
DOIs
Publication statusPublished - 2012
EventConference on FIRST STARS - From Hayashi to the Future 2012 - Kyoto, Japan
Duration: 21 May 201225 May 2012
Conference number: 4th

Publication series

NameAIP Conference Proceedings
PublisherAIP Publishing
Volume1480
ISSN (Print)0094-243x

Conference

ConferenceConference on FIRST STARS - From Hayashi to the Future 2012
CountryJapan
CityKyoto
Period21/05/1225/05/12

Keywords

  • abundances
  • nuclear reactions
  • nucleosynthesis
  • stars: abundances
  • stars: AGB and post-AGB

Cite this

Stancliffe, R. J., Lugaro, M. A., Karakas, A. I., & Rijs, C. (2012). The s-process at low metallicity. In M. Umemura, & K. Omukai (Eds.), First Stars IV - From Hayashi to the Future: Kyoto, Japan; 21-25 May 2012 (pp. 156-159). (AIP Conference Proceedings; Vol. 1480). USA: AIP Publishing. https://doi.org/10.1063/1.4754347
Stancliffe, Richard J. ; Lugaro, Maria A. ; Karakas, Amanda I. ; Rijs, Carlos. / The s-process at low metallicity. First Stars IV - From Hayashi to the Future: Kyoto, Japan; 21-25 May 2012. editor / Masayuki Umemura ; Kazuyuki Omukai. USA : AIP Publishing, 2012. pp. 156-159 (AIP Conference Proceedings).
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title = "The s-process at low metallicity",
abstract = "We present models for the slow neutron-capture process (s-process) in asymptotic giant branch stars of metallicity [Fe/H] = -2.3 and masses 0.9 - 6M⊙. The models where the 13C burns radiatively (stars of around 2M⊙) produce an overall good match to carbon-enhanced metalpoor (CEMP) stars showing barium enhancements (CEMP-s). On the other hand, none of our models can provide a match to the composition of CEMP stars showing both barium and europium enhancements (CEMP-s/r). The models fail to reproduce the observed Eu abundances, and they also fail to reproduce the correlation between the Eu and Ba abundances. They also cannot match the ratio of heavy-to-light s-process elements observed in many CEMP-s/r stars, which can be more than 10 times higher than in the Solar System. This work has been published [1] and the interested reader should refer to that work for further details, included published tables of yields.",
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Stancliffe, RJ, Lugaro, MA, Karakas, AI & Rijs, C 2012, The s-process at low metallicity. in M Umemura & K Omukai (eds), First Stars IV - From Hayashi to the Future: Kyoto, Japan; 21-25 May 2012. AIP Conference Proceedings, vol. 1480, AIP Publishing, USA, pp. 156-159, Conference on FIRST STARS - From Hayashi to the Future 2012, Kyoto, Japan, 21/05/12. https://doi.org/10.1063/1.4754347

The s-process at low metallicity. / Stancliffe, Richard J.; Lugaro, Maria A.; Karakas, Amanda I.; Rijs, Carlos.

First Stars IV - From Hayashi to the Future: Kyoto, Japan; 21-25 May 2012. ed. / Masayuki Umemura; Kazuyuki Omukai. USA : AIP Publishing, 2012. p. 156-159 (AIP Conference Proceedings; Vol. 1480).

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearch

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AU - Karakas, Amanda I.

AU - Rijs, Carlos

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N2 - We present models for the slow neutron-capture process (s-process) in asymptotic giant branch stars of metallicity [Fe/H] = -2.3 and masses 0.9 - 6M⊙. The models where the 13C burns radiatively (stars of around 2M⊙) produce an overall good match to carbon-enhanced metalpoor (CEMP) stars showing barium enhancements (CEMP-s). On the other hand, none of our models can provide a match to the composition of CEMP stars showing both barium and europium enhancements (CEMP-s/r). The models fail to reproduce the observed Eu abundances, and they also fail to reproduce the correlation between the Eu and Ba abundances. They also cannot match the ratio of heavy-to-light s-process elements observed in many CEMP-s/r stars, which can be more than 10 times higher than in the Solar System. This work has been published [1] and the interested reader should refer to that work for further details, included published tables of yields.

AB - We present models for the slow neutron-capture process (s-process) in asymptotic giant branch stars of metallicity [Fe/H] = -2.3 and masses 0.9 - 6M⊙. The models where the 13C burns radiatively (stars of around 2M⊙) produce an overall good match to carbon-enhanced metalpoor (CEMP) stars showing barium enhancements (CEMP-s). On the other hand, none of our models can provide a match to the composition of CEMP stars showing both barium and europium enhancements (CEMP-s/r). The models fail to reproduce the observed Eu abundances, and they also fail to reproduce the correlation between the Eu and Ba abundances. They also cannot match the ratio of heavy-to-light s-process elements observed in many CEMP-s/r stars, which can be more than 10 times higher than in the Solar System. This work has been published [1] and the interested reader should refer to that work for further details, included published tables of yields.

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KW - stars: AGB and post-AGB

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PB - AIP Publishing

CY - USA

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Stancliffe RJ, Lugaro MA, Karakas AI, Rijs C. The s-process at low metallicity. In Umemura M, Omukai K, editors, First Stars IV - From Hayashi to the Future: Kyoto, Japan; 21-25 May 2012. USA: AIP Publishing. 2012. p. 156-159. (AIP Conference Proceedings). https://doi.org/10.1063/1.4754347