GALACTIC CHEMICAL EVOLUTION AND SOLAR s-PROCESS ABUNDANCES: DEPENDENCE ON THE 13C-POCKET STRUCTURE

By S. Bisterzo, C. Travaglio, Roberto Gallino, Michael Wiescher, F. Käppeler. 2014

159 citations recorded by the source corpus.

We study the s-process abundances (A ≳ 90) at the epoch of the solar system formation. Asymptotic giant branch yields are computed with an updated neutron capture network and updated initial solar abundances. We confirm our previous results obtained with a Galactic chemical evolution (GCE) model: (1) as suggested by the s-process spread observed in disk stars and in presolar meteoritic SiC grains, a weighted average of s-process strengths is needed to reproduce the solar s distribution of isotopes with A > 130; and (2) an additional contribution (of about 25%) is required in order to represent the solar s-process abundances of isotopes from A = 90 to 130. Furthermore, we investigate the effect of different internal structures of the 13C pocket, which may affect the efficiency of the 13C(α, n)16O reaction, the major neutron source of the s process. First, keeping the same 13C profile adopted so far, we modify by a factor of two the mass involved in the pocket; second, we assume a flat 13C profile in the pocket, and we test again the effects of the variation of the mass of the pocket. We find that GCE s predictions at the epoch of the solar system formation marginally depend on the size and shape of the 13C pocket once a different weighted range of 13C-pocket strengths is assumed. We obtain that, independently of the internal structure of the 13C pocket, the missing solar system s-process contribution in the range from A = 90 to 130 remains essentially the same.

Subfields: Astronomy and Astrophysics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/6be4f344fcc4fddca9a30c3ce4f527d2ef409b44

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In Astronomy and Astrophysics

1. A. Karakas
2. M. Lugaro
3. A. Chieffi
4. M. Limongi
5. C. Abia
6. S. Cristallo
7. N. Prantzos
8. J. Lattanzio

In Statistical and Nonlinear Physics

1. M. Lugaro
2. S. Cristallo
3. C. Abia
4. A. Karakas
5. A. Chieffi
6. M. Limongi
7. C. Kobayashi
8. J. Lattanzio

Citations in the corpus

• STELLAR YIELDS FROM METAL-RICH ASYMPTOTIC GIANT BRANCH MODELS (2016, background): “As found elsewhere (Travaglio et al. 2004; Bisterzo et al. 2014) the yields from the intermediate-mass AGB stars do not play an important role at these metallicities, except for N and Rb. Production of a substantial yield of Rb from AGB stars requires the contribution from stars of ≈ 4M that…”
• Chemical evolution with rotating massive star yields - I. The solar neighbourhood and the s-process elements (2018, background): “Travaglio et al. (2004) and, more recently, Bisterzo et al. (2014, 2017), reported a deficit of the predicted solar system abundances of the s-only isotopes in the Sr-Te region, connecting this deficit to the existence of a missing contribution: the so-called solar light element primary process…”