Enhanced production of barium in low-mass stars: evidence from open clusters

Valentina D'Orazi, Laura Magrini, Sofia Randich, Daniele Galli, Maurizio Busso, Paola Sestito

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Abstract

We report the discovery of a trend of increasing barium abundance with decreasing age for a large sample of Galactic open clusters. The observed pattern of [Ba/Fe] versus age can be reproduced with a Galactic chemical evolution model only assuming a higher Ba yield from the s-process in low-mass stars than the average one suggested by parameterized models of neutron-capture nucleosynthesis. We show that this is possible in a scenario where the efficiency of the extra-mixing processes producing the neutron source 13C is anticorrelated with the initial mass, with a larger efficiency for lower masses. This is similar to the known trend of extended mixing episodes acting in H-rich layers and might suggest a common physical mechanism.

Original languageEnglish
JournalThe Astrophysical Journal
Volume693
Issue number1 PART 2
DOIs
Publication statusPublished - 2009
Externally publishedYes

Keywords

  • Galaxy: abundances
  • Galaxy: disk
  • Galaxy: evolution
  • Open clusters and associations: general

Cite this

D'Orazi, V., Magrini, L., Randich, S., Galli, D., Busso, M., & Sestito, P. (2009). Enhanced production of barium in low-mass stars: evidence from open clusters. The Astrophysical Journal, 693(1 PART 2). https://doi.org/10.1088/0004-637X/693/1/L31