摘要
Employing recent TP-AGB synthesis, we have carried out a detailed study of Mira variables by means of a population synthesis code. We estimate that the total number of Mira variables in the Galaxy is from about 100 000 to 600 000 and their average lifetimes are between about 150 000 and 830 000 yr. The ratio of the number of O-Mira variables to that of C-Mira variables ranges from about 0.68 to 6.2. The effects of input physical parameters （mass loss rate, the minimum core mass for the third dredge-up, the third dredge-up efficiency and theoretical criterion for selecting Mira variables） on the Mira population are discussed.
Employing recent TP-AGB synthesis, we have carried out a detailed study of Mira variables by means of a population synthesis code. We estimate that the total number of Mira variables in the Galaxy is from about 100 000 to 600 000 and their average lifetimes are between about 150 000 and 830 000 yr. The ratio of the number of O-Mira variables to that of C-Mira variables ranges from about 0.68 to 6.2. The effects of input physical parameters （mass loss rate, the minimum core mass for the third dredge-up, the third dredge-up efficiency and theoretical criterion for selecting Mira variables） on the Mira population are discussed.
基金
funded by the National Natural Science Foundation of China(NSFC) under Nos. 10763001 and 10647003
the Natural Science Foundation of Xinjiang underNo. 2009211B01
the Scientific Research Program of the Higher Education Institution of Xinjiangunder No. XJEDU2008S12
