Comparing the Nucleosynthesis Parameters of s+r Stars and Ba Stars
In this paper,we use a parametric model of the asymptotic giant branch (AGB) stars,in which the 13C neutron source is activated in radiative conditions during the interpulse periods,to calculate the nucleosynthesis in 29 very metal-poor double-enhanced stars (i.e. s+r stars) and 26 barium stars (i.e. Ba stars),respectively. Through a statistical analyzing on the corresponding parameters obtained for the above stars,we get the possible conditions which the s+r stars formed in. We find that the value of neutron exposures of most s+r stars is greater than that of Ba stars. In the very metal-poor stars,the Ba stars stars should belong to the binary systems with large initial orbital separation,by comparing the s-process-component coefficient (Cs) values with those of s+r stars. For s+r stars,there is strong correlation between their Cs and Cr(r-process-component coefficient) but no correlation for Ba stars. This strongly confirms the possibility that the s+r stars should form through the accretion-induced collapse (AIC) or type 1.5 supernova mechanism.
nucleosynthesis stars:abundances AGB and post-AGB
Wen-Yuan Cui Dong-Nuan Cui Bo Zhang
Department of Physics,Hebei Normal University,113 Yuhua Dong Road,Shijiazhuang 050016,P.R.China
国际会议
The 252th Symposium of the International Astronomical Union(国际天文学联合会第252届研讨会)
海南三亚
英文
113-114
2008-04-06（万方平台首次上网日期，不代表论文的发表时间）