标题： 星系全局参数之间的相关性 显示英文标题

标题： Correlation between Global Parameters of Galaxies

摘要： 近期，迪士尼等人（2008）发现控制星系动力学的五个基本参数之间存在显著的相关性：R50、R90、Lr、Md 和 MHI。他们指出这与ΛCDM模型相冲突，该模型预测宇宙结构是从下到上分层形成的。鉴于这一问题的重要性，我们基于一个显著更大的数据库和两个额外参数——近红外J波段的LJ和RJ——对星系的整体参数进行了类似的分析。我们使用了来自阿雷西博原子气体性质巡天、斯隆数字巡天以及两微米全天巡天的数据库来研究星系的光学性质、近红外性质和原子气体性质。我们进行了主成分分析（PCA），以寻找这些观测变量之间的关系，并确认迪士尼等人工作的五个参数确实相关。第一个主成分主导了这五个参数之间的相关性，并能解释数据中86%的变化。当加入颜色（g-i）时，第一主成分仍然占主导地位，而颜色形成了几乎与其他参数独立的第二个主成分。我们的近红外PCA总体趋势与此类似，只是颜色（i-J）似乎与所有其他参数更加解耦。第一个主成分的主导地位表明星系的结构是由单一物理参数决定的。这证实了迪士尼等人观测结果。然而，基于重子物理在星系形成中的重要性，我们认为层次结构形成情景和冷暗物质的概念不一定有缺陷。 显示英文摘要

摘要： Recently Disney et al. (2008) found a striking correlation among the five basic parameters that govern the galactic dynamics: R50, R90, Lr, Md, and MHI . They suggested that this is in conflict with the LCDM model, which predicts the hierarchical formation of cosmic structures from bottom up. In light of the importance of the issue, we performed a similar analysis on global parameters of galaxies with a significantly larger database and two additional parameters, LJ and RJ, of the near-infrared J band. We used databases from the Arecibo Legacy Fast Arecibo L-band Feed Array Survey for the atomic gas properties, the Sloan Digital Sky Survey for the optical properties, and the Two Micron All Sky Survey for the near-infrared properties, of the galaxies. We conducted principal component analysis (PCA) to find relations among these observational variables and confirmed that the five parameters in the work of Disney et al. are indeed correlated. The first principal component dominates the correlations among the five parameters and can explain 86% of the variation in the data. When color (g - i) is included, the first component still dominates and the color forms a second principal component that is almost independent of other parameters. The overall trend in our near-infrared PCA is very similar, except that color (i - J) seems even more decoupled from all other parameters. The dominance of the first principal component suggests that the structure of galaxies is governed by a single physical parameter. This confirms the observational results in Disney et al. However, based on the importance of the baryon physics in galaxy formation, we are not convinced that the hierarchical structure formation scenario and the notion of cold dark matter are necessarily flawed.