星风吸积引起的钡星重元素超丰

S process Element Overabundances of Ba Stars Through Wind Accretion

首先指出目前星风吸积模型中理论上的不自洽，考虑到δｒ≠０，重新推导轨道参量变化方程，消去了理论上的不自洽．提出一个新模型：首次将星风吸积同内禀ＡＧＢ星核合成模型结合起来计算钡（Ｂａ）星的重元素超丰，并将计算结果与观测值进行了比较．各参量按标准情况取值时，计算结果不太理想．取Ｂｏｎｄｉｈｏｙｌｅ吸积率的０．５倍或取较大的星风速率时，对于较长轨道周期（Ｐ＞１０００天）的Ｂａ星，计算结果与观测值基本符合；而较短轨道周期（Ｐ＜６００天）的Ｂａ星。

The lack of self consistency in the current wind accretion models is pointed out. Taking account of δr ≠ 0 , the modification equations of orbital parameters are re deduced. Combined with wind accretion scenarios,calculations of nucleosynthesis for intrinsic AGB stars are first used to calculate s-process enrichments of Ba stars. Comparisons are also made between the predictions of calculations and the observations. It is found that predictions from the model for the standard case are an upper limit to the observations . Better agreements are obtained either by increasing the wind velocity or reducing the accretion rate.