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arXiv 0704.0774astro-ph
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来自COMBO-17的Abell 901/902超星系团的星系形态和环境

Galaxy morphologies and environment in the Abell 901/902 supercluster from COMBO-17

K. P. Lane, M. E. Gray, A. Aragon-Salamanca, C. Wolf, K. Meisenheimer

摘要:

本文对COMBO-17巡天的A901/902超星系团中的星系进行了形态学研究。用三个独立的分类器对光度红移在0.155 < z_phot < 0.185范围内的570个星系进行了目视分类,M_V=-18。这些形态分类进行比较,当地的星系密度,距离最近的集群中心,当地的表面质量密度弱透镜,光度分类。在高的局部星系密度下,log(Sigma_10 /Mpc^2)> 1.5,发现了经典的形态-密度关系,还发现了形态和局部投影表面质量密度之间的相关性,但没有观察到与最近星系团距离的趋势。这支持了局部环境对星系形态比整体星系团性质更重要的发现。按颜色分类的形态目录显示,在显示晚型形态的星系中,蓝色星系占主导地位,而在早型种群中,红色星系占相应的主导地位。利用COMBO-17的17波段测光,我们进一步按照Wolf等人(2005)的公式将红超星系团序列分裂为老的被动星系和有年轻恒星和尘埃的星系。我们发现,尘埃恒星形成的人口描述了一个中间形态组之间的晚型和早型星系,支持这一假设,即场和组螺旋星系转化为S 0 s,也许,椭圆星系在集群下降。

英文摘要:

We present a morphological study of galaxies in the A901/902 supercluster from the COMBO-17 survey. A total of 570 galaxies with photometric redshifts in the range 0.155 < z_phot < 0.185 are visually classified by three independent classifiers to M_V=-18. These morphological classifications are compared to local galaxy density, distance from the nearest cluster centre, local surface mass density from weak lensing, and photometric classification. At high local galaxy densities, log(Sigma_10 /Mpc^2) > 1.5, a classical morphology-density relation is found. A correlation is also found between morphology and local projected surface mass density, but no trend is observed with distance to the nearest cluster. This supports the finding that local environment is more important to galaxy morphology than global cluster properties. The breakdown of the morphological catalogue by colour shows a dominance of blue galaxies in the galaxies displaying late-type morphologies and a corresponding dominance of red galaxies in the early-type population. Using the 17-band photometry from COMBO-17, we further split the supercluster red sequence into old passive galaxies and galaxies with young stars and dust according to the prescription of Wolf et al. (2005). We find that the dusty star-forming population describes an intermediate morphological group between late-type and early-type galaxies, supporting the hypothesis that field and group spiral galaxies are transformed into S0s and, perhaps, ellipticals during cluster infall.

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。

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