Age and Mass Estimates for 41 Star Clusters in M33

摘要

In this second paper of our series, we estimate the age of 41 star clusters, which were detected by Melnick & D'odorico in the nearby spiral galaxy M33, by comparing the integrated photometric measurements with theoretical stellar population synthesis models of Bruzual & Chariot. Also, we calculate the mass of these star clusters using the theoretical M/L_v ratio. The results show that, these star clusters formed continuously in M33 from ～ 7 x 10~6 - 10~(10) years and have masses between ～10~3 and 2 x 10~6 solar mass. M33 frames were observed as a part of the BATC Multicolor Survey of the sky in 13 intermediate-band filters from 3800 to 10 000A. The relation between age and mass confirms that the sample star cluster masses systematically decrease from the oldest to the youngest.