无监督的Galerkin分类。I. ICA特征选择
Unsupervised Classification of Galaxies. I. ICA feature selection
摘要：
对星系的主观分类可能会误导我们对星系形成和演化起源的探索，因为这必然限于少数特征。人类的思维无法理解多重参数空间中复杂的相关性，而多元分析是理解各种对象之间差异的最佳工具。在这一系列的论文中，362,923星系的客观分类从增值星系表（VAGC）进行了两种方法的多元分析的帮助下。首先，独立成分分析（ICA）被用来确定一组衍生的独立成分，这些独立成分是47个观测特征（即电离线，Lick指数，光度和形态学特性，恒星形成率等）的线性组合。的星系。随后，K-均值聚类分析应用于九个独立的组件，以获得十个不同的和同质的群体。在这第一篇论文中，我们描述的方法和主要结果。看来，九个独立分量代表了星系的完整物理描述（速度色散，电离，金属丰度，表面亮度和结构）。我们发现，我们的10组基本上可以被放置到传统的和经验的类（从颜色大小和发射线诊断图，早期与晚期类型），尽管经典的相应功能（颜色，线比和形态）没有显着相关的9个独立组件。更详细的物理解释将在随后的论文中进行。
英文摘要：
Subjective classification of galaxies can mislead us in the quest of the origin regarding formation and evolution of galaxies since this is necessarily limited to a few features. The human mind is not able to apprehend the complex correlations in a manyfold parameter space, and multivariate analyses are the best tools to understand the differences among various kinds of objects. In this series of papers, an objective classification of 362,923 galaxies from the Value Added Galaxy Catalogue (VAGC) is carried out with the help of two methods of multivariate analysis. First, Independent Component Analysis (ICA) is used to determine a set of derived independent components that are linear combinations of 47 observed features (viz. ionized lines, Lick indices, photometric and morphological properties, star formation rates etc.) of the galaxies. Subsequently, a K-means cluster analysis is applied on the nine independent components to obtain ten distinct and homogeneous groups. In this first paper, we describe the methods and the main results. It appears that the nine Independent Components represent a complete physical description of galaxies (velocity dispersion, ionisation, metallicity, surface brightness and structure). We find that our ten groups can be essentially placed into traditional and empirical classes (from colour-magnitude and emission-line diagnostic diagrams, early- vs late-types) despite the classical corresponding features (colour, line ratios and morphology) being not significantly correlated with the nine Independent Components. More detailed physical interpretation of the groups will be performed in subsequent papers.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
