摘要
本文对宇宙钾的丰度作了一简要评介。星族Ⅰ的太阳型恒星大气锂的丰度随恒星质量的减小和年龄的增大而迅速降低。恒星大气锂的衰减主要是发生在恒星进入主序后的阶段。似乎有迹象表明,恒星大气锂的衰减速率随恒星的年龄增大而减小。与星族Ⅰ恒星相反,贫金属的星族Ⅱ的F和早型G型矮星大气锂丰度弥散很小,且其丰度比年轻的星族Ⅰ恒星和星际介质锂的丰度约低一个量级。标准的大爆炸宇宙模型预期较低的原始宇宙锂丰度,它大致同极端贫金属星族ⅡF型矮星的大气锂丰度相合,但理论预期的重子密度却远小于从星系和星系团大尺度结构和动力学所推求的宇宙密度。
This paper reviews the lithium abundance problem in astrophysics. The observations show that the lithium abundance of the solar-type stars decreases sharply with decreasing of their mass and increasing of their age. The Li depletion for the solar-type stars is set chiefly in the MS, nob before. It seems that the rate of Li depletion decreases with increasing of the age of stars. In. contrast with Pup I stars the Li abundances of Pup Ⅱ F- and early G-type dwarfs show a very small dispersion and they are about an order of magnitude smaller than the value of the young Pup I stars. The standard Big Bang nucleosynthesis predicts a low primordial Li abundance, which is consistent approximately with the observations of the warmer Pup Ⅱ dwarfs.
出处
《天文学进展》
CSCD
北大核心
1992年第2期91-102,共12页
Progress In Astronomy
