Abundance Analysis of r plus s Stars: r-Process Abundance Comparison between r plus s Stars and r-rich Stars

作者：Liang, Shuai^*; Li, Hongjie; Shen, Xiaojing; Cui, Wenyuan; Zhang, Bo

来源：Publications of the Astronomical Society of the Pacific, 2012, 124(914): 304-315.

DOI：10.1086/665526

• METAL-POOR STARS
• NEUTRON-CAPTURE ELEMENTS
• ASYMPTOTIC GIANT BRANCH
• CARBON-RICH
• SPECTROSCOPIC ANALYSIS
• NUCLEOSYNTHESIS PROCESSES
• DISPERSION SPECTROGRAPH
• EARLY GALAXY
• SURVEY HERES
• BINARY

The chemical abundances of the r + s stars can give us excellent information for setting constraints on models of s- and r-process nucleosynthesis. In this article, we fit the element abundances of 32 r + s or s- rich stars by using a parametric model. We find that the r-process abundance pattern related to r + s stars is similar to the pattern of r-rich stars. On the other hand, the abundance pattern of light elements and iron group elements for the r + s stars is very close to the pattern for weak r-process stars. The r + s stars and r-rich stars are initially formed in the molecular cloud, which had been polluted by weak r-process material. The yields of r-process related to r + s stars are proportional to their metallicity. Although the origin and site of the s- process are quite different from those of the r-process, there is a strong correlation between the enhancement level of the s- process and r-process in r + s stars. This implies that r-process matter accreted from the origin of the r-process, such as AIC or SN 1.5, has an increasing trend with increasing s-process matter accreted from the AGB stars.

• 出版日期2012-4
• 单位河北师范大学