白矮星演化与宇宙纪年学

White Dwarf Evolution and Cosmochronology

近几年白矮星研究在理论与观测方面都取得了很大进展,这推动了白矮星宇宙纪年学的应用和发展。白矮星宇宙纪年学,即利用白矮星的演化结果计算白矮星理论光度函数,并通过与观测光度函数的对比来确定天体年龄。简要描述了白矮星的基本性质,回顾了白矮星演化研究的历史和基本方法;介绍了白矮星宇宙纪年学研究的基本原理及其在银盘、球状星团、疏散星团以及银晕年龄确定方面的应用现状。白矮星宇宙纪年学是一个很新的研究领域,但它已经在确定天体年龄方面显示出很大的潜力。最后讨论了目前研究中存在的问题,并提出今后需要进一步研究的几项工作。

The recent significant progress on both the theoretical and observational researches on white dwarfs promotes the application and development of white dwarf cosmochronology. The idea of such a chronometry is to calculate the theoretical luminosity function using white dwarf cooling tracks and compare it with observational luminosity function to constrain the ages of various populations of evolved stars in the Galaxy accordingly. In this review, we first briefly describe the basic properties of white dwarfs, and then review the history and basic methods of white dwarf evolution researches. We also describe the basic principle of white dwarf cosmochronology and its application in defining the age of the Galactic disk, globular clusters, open clusters and Galactic halo. Although white dwarf cosmochronology is still in its infancy, it already shows its potential as a powerful tool for estimating the ages of the various objects. Finally we discuss the uncertainties existed in current research and suggest some further investigations on it.