OPAL不透明度对恒星结构和演化模型的影响

The Influences of OPAL Opacities on Stellar Structure and Evolution Models

本文利用国际上最新公布的OPAL不透明度表及相应的化学丰度，计算了三颗不同初始质量的星族互恒星的非守恒演化模型，并和过去长期采用的LAOL不透明度的结果进行详细比较，得出以下主要结论：（1）恒星HR图中的演化轨迹光度降低，主序位置明显向红方向移动；（2）恒星中心H，He燃烧寿命大大延长了；（3）小质量星氢燃烧核和对流核都变小，大、中质量星的中心对流核和燃烧核都有所增大；（4）恒星中心温度－密度关系基本不受影响．

The updated Livermore Opacity tables (OPAL) and the corresponding abundallce data have been used ot compute the non-conservatioll evolutionary models of three population I stars with different initial mass. A detailed comparison between the OPAL and previous Los Alamos Opacity (LAOL) results have been made. our main results are: (1) The use of OPAL produces appreciable changes in the HR diagrams for low-, intermediate-mass, and massive stars. In all cases, the tracks shift to significantly lower luminosity and effective temperature with respect to those by the old LAoL models. (2) The lifetimes in the H and He burning phases have increased greatly. (3) For low mass stars, the size of the convective core and H-burning core is smaller. While for intermediate mass and massive stars, their convective and burning core are slightly larger. (4) The Tc-pc relation is insensitive to the differences in opacity tables.