The origin of the lead-rich stars in the Galactic halo: investigation of model parameters for the s-process

@article{Cui2006TheOO,
  title={The origin of the lead-rich stars in the Galactic halo: investigation of model parameters for the s-process},
  author={Wenyuan Cui and B. Zhang Naoc and China Department of Physics and Hebei Normal University and China.},
  journal={Monthly Notices of the Royal Astronomical Society},
  year={2006},
  volume={368},
  pages={305-309}
}
  • W. Cui, B. Z. Naoc, China.
  • Published 2 March 2006
  • Physics
  • Monthly Notices of the Royal Astronomical Society
Several stars at the low-metallicity extreme of the Galactic halo show large spreads of lead and associated 'heavy' s-process elements ([Pb/hs]). Theoretically, an s-process pattern should be obtained from an AGB star with a fixed metallicity and initial mass. For the third dredge-up and the s-process model, several important properties depend primarily on the core mass of AGB stars. Zijlstra reported that the initial-to-final mass relation steepens at low metallicity, due to low mass-loss… 

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References

SHOWING 1-10 OF 38 REFERENCES
Low-mass supernovae in the early Galactic halo: source of the double r/s-process enriched halo stars?
Several stars at the low-metallicity extreme of the Galactic halo ([Fe/H]= -2.5) show strong enhancements of both s-process and r-process elements. The presence of s-process elements in main-sequence
More lead stars
The standard model for the operation of the s-process in asymptotic giant branch (AGB) stars predicts that low-metallicity ([Fe/H] ≲ -1) AGB stars should exhibit large overabundances of Pb and Bi as
Discovery of three lead-rich stars
TLDR
Analysis shows that three metal-poor stars are more enriched in lead than in any other element heavier than iron, and excellent agreement between the observed and predicted abundances reinforces current understanding of the detailed operation of the s-process deep in the interiors of AGB stars.
Galactic Chemical Evolution of Heavy Elements: From Barium to Europium
We follow the chemical evolution of the Galaxy for elements from Ba to Eu, using an evolutionary model suitable for reproducing a large set of Galactic (local and nonlocal) and extragalactic
Neutron Capture Elements in s-Process-Rich, Very Metal-Poor Stars
We report abundance estimates for neutron capture elements, including lead (Pb), and nucleosynthesis models for their origin, in two carbon-rich, very metal-poor stars, LP 625-44 and LP 706-7. These
The s-Process in Metal-Poor Stars: Abundances for 22 Neutron-Capture Elements in CS 31062-050
The CH star CS 31062-050 ([Fe/H] = -2.42) is one of the most useful stars yet discovered for evaluating the s-process in metal-poor stars. It is very abundant in heavy elements (e.g., [La/Fe] = 2.2),
A Subaru/High Dispersion Spectrograph Study of Lead (Pb) Abundances in Eight s-Process Element-rich, Metal-poor Stars
We report the abundances of neutron-capture elements in eight carbon-rich, metal-poor (-2.7 ≤ [Fe/H] ≤ -1.9) stars observed with the Subaru Telescope High Dispersion Spectrograph. The derived
Nucleosynthesis of s-elements in zero-metal AGB stars
Contrary to previous expectations, recent evolutionary models of zero-metallicity stars show that the development of mixing episodes at the beginning of the AGB phase allows low- and
Neutron Capture in Low-Mass Asymptotic Giant Branch Stars: Cross Sections and Abundance Signatures
Recently improved information on the stellar (n, γ) cross sections of neutron magic nuclei at N = 82, and in particular of 142Nd, turn out to represent a sensitive test for models of s-process
Evolution and Nucleosynthesis in Low-Mass Asymptotic Giant Branch Stars. II. Neutron Capture and the s-Process
We present a new analysis of neutron capture occurring in low-mass asymptotic giant branch (AGB) stars suffering recurrent thermal pulses. We use dedicated evolutionary models for stars of initial
...
...