A Statistical Comparison of Line Strength Variations in Coma and Cluster Galaxies at z ~ 0·3

Publications of the Astronomical Society of Australia

Lewis A. Jones¹ 

[1] Warrick J. Couch

关键词: galaxies: individual (Coma;    AC103;    AC114;    AC118);    galaxies: clusters;    galaxies: evolution;    galaxies: formation;    methods: data analysis;   

DOI  :  10.1071/AS98309

学科分类：天文学(综合)

来源: CSIRO

【 摘 要 】

We present a statistical comparison between spectral line strength variations in Coma galaxies and galaxies in three rich clusters at z ~ 0.3. Using a principal component analysis, we have transformed the observable quantities, the line strengths, into new mutually orthogonal axes and found two specific results. First, more independent parameters are required to account for the line strength variations in the distant cluster data than in the Coma data, and second, line strengths which are not correlated in the distant cluster data are strongly coupled in the Coma data. These results suggest that galaxies in clusters have been homogenised such that most of the information from the conditions present at their formation has been destroyed. Hence, it may be possible that the present-day homogeneity of early-type galaxy properties, e.g. the fundamental plane relation, does not require a single formation scenario, but that a variety of formation scenarios for different galaxies could still yield the observed behaviour of nearby galaxies.

【 授权许可】

Unknown