期刊
ASTROPHYSICAL JOURNAL
卷 576, 期 2, 页码 L113-L116出版社
IOP Publishing Ltd
DOI: 10.1086/343759
关键词
galaxies : formation; galaxies : individual (M87); galaxies : star clusters
Relative ages for the globular cluster (GC) subpopulations in the Virgo giant elliptical galaxy M87 (NGC 4486) have been determined from Stromgren photometry obtained with the Wide Field Planetary Camera 2 on board the Hubble Space Telescope. Using a variety of population synthesis models, and assuming the GC mass at the turnover of the luminosity function is the same for both subpopulations, differential ages have been determined from the observed magnitudes at the turnover of the globular cluster luminosity function and from the mean color of each subpopulation. We measure an age difference between the two subpopulations of 0.2+/-1.5 (systematic) +/- 2 (random) Gyr, in the sense that the blue GCs are formally older. Thus, to within our measurement errors, the two subpopulations are found to be coeval. Combined with previous spectroscopic age determinations for M87 GCs, our results favor a picture in which the GCs associated with this galaxy are formed at high redshift and within a period of a few gigayears.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据