Stellar ages and metallicities of nearby elliptical galaxies

作者：Tang Bai Tian^*; Gu Qiu Sheng; Huang Song

来源：Research in Astronomy and Astrophysics, 2009, 9(11): 1215-1229.

DOI：10.1088/1674-4527/9/11/005

• galaxies: elliptical and lenticular, cD
• galaxies: statistics
• galaxies: stellar content

Stellar ages and metallicities are crucial for understanding the formation and evolution of elliptical galaxies. However, due to the age-metallicity degeneracy, it is hard to measure these two parameters accurately with broad-band photometry. In this paper, we observed high-resolution spectra for a sample of 20 nearby elliptical galaxies (EGs) with the NAOC 2.16 in telescope, and determined stellar ages and metallicities by using the empirical population synthesis and Lick/IDS index system methods. We found that stellar ages from these two methods are consistent with each other for purely old EGs; however, stellar metalticities show a zeropoint offset of 0.5 Z(circle dot). Our results confirm that stellar populations in low-density environment galaxies are more diverse compared to their high-density counterparts. We also investigated the element abundance-galaxy mass relation for nearby elliptical galaxies.

• 出版日期2009-11
• 单位南京大学