THE ADVANCED CAMERA FOR SURVEYS FORNAX CLUSTER SURVEY. VII. HALF-LIGHT RADII OF GLOBULAR CLUSTERS IN EARLY-TYPE GALAXIES
THE ADVANCED CAMERA FOR SURVEYS FORNAX CLUSTER SURVEY. VII. HALF-LIGHT RADII OF GLOBULAR CLUSTERS IN EARLY-TYPE GALAXIES
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DOI：
10.1088/0004-637x/715/2/1419
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发表时间：
2010-03
期刊：
影响因子：
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通讯作者：
K. Masters;A. Jordán;P. Côté;L. Ferrarese;J. Blakeslee;L. Infante;E. Peng;S. Mei;M. West
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文献类型：
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作者：
K. Masters;A. Jordán;P. Côté;L. Ferrarese;J. Blakeslee;L. Infante;E. Peng;S. Mei;M. West
我们测量了43个星系中球状星团(GC)的半光半径，这些半光半径是由先进巡天相机(ACS)的Fornax星系团调查得出的。我们利用这些数据扩展了以前的工作，其中研究了ACS室女座星系团调查中早期类型星系GC的半光半径的环境相关性，并建议将修正的平均半光半径(根据观测到的环境趋势进行修正)作为一个可靠的距离指示器。这项工作既增加了环境相关性研究的样本量，又增加了将修正的半光半径作为可能的距离指示器的研究的杠杆(因为Fornax位于比处女座星系团更远的距离)。我们使用主成分分析和二维标度关系来研究GC大小的环境依赖性。我们在很大程度上证实了Jordán等人所展示的环境相关性，但发现证据表明，GC系统的平均半光半径与星系星等之间存在剩余关联，而其他关联之间存在细微差异--因此，可能不存在对低光度星系GC系统的半光半径的普遍修正。在早期类型星系中，决定GC大小的主要因素是GC颜色。红色GC<rh>=2.8±0.3pC，蓝色GC<rh>=3.4±0.3pC。我们表明，对于明亮的早期类型星系(MB<；−19 MAG)，GC系统未经校正的平均半光半径本身就是一个很好的距离指示器(误差∼为11%)，在大光学望远镜的高角分辨率自适应光学时代，有可能达到宇宙学上感兴趣的距离。
We measure the half-light radii of globular clusters (GCs) in 43 galaxies from the Advanced Camera for Surveys (ACS) Fornax Cluster Survey. We use these data to extend previous work in which the environmental dependencies of the half-light radii of GCs in early-type galaxies in the ACS Virgo Cluster Survey were studied, and a corrected mean half-light radius (corrected for the observed environmental trends) was suggested as a reliable distance indicator. This work both increases the sample size for the study of the environmental dependencies, and adds leverage to the study of the corrected half-light radius as a possible distance indicator (since Fornax lies at a larger distance than the Virgo cluster). We study the environmental dependencies of the size of GCs using both a Principal Component Analysis as well as two-dimensional scaling relations. We largely confirm the environmental dependencies shown in Jordán et al., but find evidence that there is a residual correlation in the mean half-light radius of GC systems with galaxy magnitude, and subtle differences in the other correlations—so there may not be a universal correction for the half-light radii of lower luminosity galaxy GC systems. The main factor determining the size of a GC in an early-type galaxy is the GC color. Red GCs have 〈rh〉 = 2.8 ± 0.3 pc, while blue GCs have 〈rh〉 = 3.4 ± 0.3 pc. We show that for bright early-type galaxies (MB < −19 mag), the uncorrected mean half-light radius of the GC system is by itself an excellent distance indicator (with error ∼11%), having the potential to reach cosmologically interesting distances in the era of high angular resolution adaptive optics on large optical telescopes.