Non-standard s-process in massive rotating stars. Yields of 10-150 M⊙ models at Z = 10-3
Abstract
Context. Recent studies show that rotation significantly affects the s-process in massive stars.
Aims: We provide tables of yields for non-rotating and rotating massive stars between 10 and 150 M⊙ at Z = 10-3 ([Fe/H] = -1.8). Tables for different mass cuts are provided. The complete s-process is followed during the whole evolution with a network of 737 isotopes, from hydrogen to polonium.
Methods: A grid of stellar models with initial masses of 10, 15, 20, 25, 40, 60, 85, 120, and 150 M⊙ and with an initial rotation rate of both 0% or 40% of the critical velocity was computed. Three extra models were computed in order to investigate the effect of faster rotation (70% of the critical velocity) and of a lower 17O(α, γ) reaction rate.
Results: At the considered metallicity, rotation has a strong impact on the production of s-elements for initial masses between 20 and 60 M⊙. In this range, the first s-process peak is boosted by 2-3 dex if rotation is included. Above 60 M⊙, s-element yields of rotating and non-rotating models are similar. Increasing the initial rotation from 40% to 70% of the critical velocity enhances the production of 40 ≲ Z ≲ 60 elements by ∼0.5-1 dex. Adopting a reasonably lower 17O(α, γ) rate in the fast-rotating model (70% of the critical velocity) boosts again the yields of s-elements with 55 ≲ Z ≲ 82 by about 1 dex. In particular, a modest amount of Pb is produced. Together with s-elements, some light elements (particularly fluorine) are strongly overproduced in rotating models.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- October 2018
- DOI:
- 10.1051/0004-6361/201833283
- arXiv:
- arXiv:1807.06974
- Bibcode:
- 2018A&A...618A.133C
- Keywords:
-
- stars: massive;
- stars: rotation;
- stars: interiors;
- stars: abundances;
- stars: chemically peculiar;
- nuclear reactions;
- nucleosynthesis;
- abundances;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 16 pages, 14 figures, 4 tables. Accepted for publication in A&