质量损失对贫金属AGB星表面丰度的影响

Effect of Mass Loss on Abundances of Metal-Poor Asymptotic Giant Branch Stars

在参数化热脉冲模型的基础上,加入星风质量损失,拟合了三颗铅星(HD187861、HD224959和HD196944)和两颗非铅星(LP625-44与LP706-7)的表面丰度,计算结果都能很好地重现观测数据。同时还发现:在考虑星风质量损失的情况下,三颗铅星的平均中子辐照量均超过2(mb)-1,富氦中间壳层中约80%的物质重复经历s-过程。而对于非铅星,星风质量损失的影响可忽略不计。

Based on the parametric thermally pulsing model ,superwind mass loss is brought into the model to fit the surface abundances of three lead-rich stars （HD187861,HD196944 and HD224959） and two very metal-poor stars （LP625-44 and LP706-7）. It shows that the calculated result can fit the observed data well. And the mean neutron exposure of three lead-rich stars with superwind mass loss are larger than 2（mb）^-1,and about 80% of substance in the He inter-shell will experience s-process repeatedly. But for the other two metal-poor stars,the effect of superwind mass loss can be negligible.