The new s-process in low mass TP-AGB stars

✍ Scribed by R. Gallino; C. Arlandini; M. Lugaro; M. Busso; O. Straniero

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 450 KB
• Volume: 621
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(97)00284-4

✦ Synopsis

The s-process nucleosynthesis occurring in the Asymptotic Giant Branch phases has been computed through a post-process calculation, following the results of stellar evolutionary models obtained with the FRANEC code for low mass stars (1-3 M®) with metallicity Z = 0.02. Mass loss with the Reimers (1975)'s parameterization was taken into account (r/= 3). Since the development of the third dredge up, we assumed that a laC-pocket is formed at the H/He discontinuity when the H-shell is inactive. Neutrons are released by the 13C(a,n)160 source in radiative conditions in the interpulse period in a thin layer of a few 10 .4 M®. The 22Ne(a,n)2SMg reaction operates marginally in convective pulses, over a material that was previously s-processed in the radiative phase and mixed with fresh Fe and H-burning ashes. The conditions under which the solar main s-process component is reproduced are discussed.