中文摘要：

Abell85是位于南半天区红移为0．055的cD星系团．基于Sloan光谱巡天数据提供的242个成员星系的光谱，利用星族合成软件sTARLIGHT获得这些成员星系的星族成份和恒星形成历史，研究星系的恒星形成性质（如特征星族年龄、金属丰度、恒星形成率等）随局域星系面密度的变化规律．结果表明，处在环境密度较高的团中心区域的星系具有较高的星族年龄和金属丰度，其比恒星形成率较低，而且近期的恒星形成活动受到显著的抑制．另外，还确认了星系金属丰度、比恒星形成率与恒星质量的相关性．

英文摘要：

Abell 85 is a cD cluster of galaxies with a redshift of 0.055, located in the southern hemisphere. Based on the SDSS （Sloan Digital Sky Survey） spectra of 242 member galaxies, the stellar synthesis code, STARLIGHT, is applied to study the stellar populations and star formation histories of member galaxies. The star formation properties of galax- ies, such as the mean stellar age, metallicity, and star formation rate, are investigated as the functions of the local surface density. Our results indicate that the massive galaxies at the high-density region of cluster core show longer mean stellar ages, higher metallicities, and lower specific star formation rates, and the recent star formation activities have been remarkably suppressed. In addition, the correlations of the metallicity and specific star for- mation rate with stellar mass are confirmed.