Nucleosynthesis of s-elements in zero-metal AGB stars

摘要: Contrary to previous expectations, recent evolutionary models of zero-metallicity stars show that the development mixing episodes at beginning AGB phase allows low- and intermediate-mass experience thermal pulses. If these stars, like their metal-rich counterparts, also partial protons from H-rich envelope into C-rich layers time third dredge-up, an extensive neutron capture nucleosynthesis leads production s-process nuclei up Pb Bi. Nucleosynthesis calculations based on stellar are performed assuming a parameterized H-abundance prole below convective dredge-up. Despite absence Fe-group elements, large flux resulting 13 C( ;n) 16 O reaction ecient elements starting captures C-Ne isotopes. Provided takes place, it is shown population III should be enriched in overall