CAJ | 학술논문

为解释著名的G矮星问题，提出银河系化学演化的三成分模型, 即由银晕、厚盘和薄盘所构成的演化模型. 相邻演化阶段间隔着一个快速坍缩过程. 对不同星族成分的演化过程分别进行模拟，并在总体上得到一个太阳附近区域的 G矮星丰度分布函数. 检验了三种不同的模型：初始富化模型、比例生成模型和坍缩模型. 利用最小二乘拟合得到最佳模型的参数. 结果表明, 太阳附近区域的化学演化受物质交换的影响较小，至少在银河系演化的晚期，可将太阳附近区域看作封闭系统. 同时，单位质量中新合成的重元素比例对三种恒星成分可分别近似为常数，其差别则说明不同星族恒星的初始质量函数存在着显著差异.
위해석저명적G왜성문제，제출은하계화학연화적삼성분모형, 즉유은훈、후반화박반소구성적연화모형. 상린연화계단간격착일개쾌속담축과정. 대불동성족성분적연화과정분별진행모의，병재총체상득도일개태양부근구역적 G왜성봉도분포함수. 검험료삼충불동적모형：초시부화모형、비례 생성모형화담축모형. 이용최소이승의합득도최가모형적삼수. 결과표명, 태양부근구역적화학연화수물질교환적영향교소，지소재은하계연화적만 기，가장태양부근구역간작봉폐계통. 동시，단위질량중신합성적중원소 비례대삼충항성성분가분별근사위상수，기차별칙설명불동성족항성적초 시질량함수존재착현저차이.
A threecomponent chemical evolution model of the Galaxy is presented, which casts a new light on the Gdwarf problem. The model is based on a scenario of the Galaxy consisting of three major evolutionary phases: halo, thick disk and thin disk, separated by two short interludes of rapid collapse. The evolution of different stellar populations are treated separately, the combination of which yields an overall metallicity distribution function for the solar neighbourhood. We tested three different models using the same set of basic equations: the ``prompt initial enrichment'' (PIE) model, the ``proportional yield'' (PPY) model and the ``collapse'' (CLP) model. Bestfit parameters are derived. The results show that the different populations have remarkably different IMFs, while mass exchange has only minimally affected the chemical evolution in the solar vicinity, so that the latter can be regarded as a closed system, at least in the late stage of Galactic evolution.