同位素丰度比^(12)C/^(13)C与恒星演化及其核过程

On Relations of ^(12)C/^(13)C Isotope Ratio and Stellar Evolution and Nucleosynthesis

近20年中在银河系及河外星系中同位素丰度比(12)C／(13)C的毫米波及光学观测取得了一些结果，同位素丰度比(12)C／(13)C在研究恒星演化及其核过程方面具有重要的意义。银河系中的(12)C／(13)C随银心距D(GC)呈梯度分布，附近河外星系中明显较高的(12)C／(13)C表明银河系中心处于一个较为宁静的物理相，恒星中不同的(12)C／(13)C值则反映了各自不同的演化阶段。进一步高精度、大样本的观测将有助于人们更加细致地了解恒星演化及其核过程。

A brief review is given for (12)C/(13)C isotope ratio in the Galaxy and extragalaxy based on the mm-wave and optical observational results, and the relations of (12)C/(13)C isotope ratio and stellar evolution and nucleosynthesis are also introduced. There is a gradient in the (12)C/(13)C ratio with D(Gc) in the Galaxy. From the comparison of Galactic and extragalactic (12)C/(13)C ratio it is indicated that the nuclear region of the Galaxy has been quiescefit for a long time. The difference of the (12)C/(13)C ratio in stars is a reflection of their different evolution phase. More accurate observations are needed for us to study the stellar evolution and its nuclear process in more detail.