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arXiv 0709.0983astro-ph
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低红移Abell星系团的光度函数

The Luminosity Function of Low-Redshift Abell Galaxy Clusters

Wayne A. Barkhouse, H. K. C. Yee, Omar López-Cruz

摘要:

本文介绍了对57个低红移Abell星系团的观测结果,以研究光度函数(LF)的径向依赖性。每个集群的动力学半径,r200,估计从光度测量集群丰富度,BGC。的LF的形状被发现与半径,这样的弱端斜率,α,一般是陡峭的集群郊区。两个Schechter函数的和比单个Schechter函数提供了对复合LF的更充分的拟合。基于红星系和蓝星系选择的LF在外观上是双峰的。对于-22 < M_Rc <-18,红色LF通常是平坦的,对于M_Rc >-18,具有α的半径依赖性陡峭。蓝色的LF比红色的LF包含更大的贡献。当M_Rc >-21时,蓝色LF具有上升的暗端分量(α ~ -1.7),与红色LF相比,其对半径的依赖性较弱。M* 的分散度被确定为0.31磁,与0.38磁的测量不确定度中位数相当。这表明LF的亮端形状在0.3磁水平上是普遍的。我们发现,M* 是不相关的集群丰富时,使用一个共同的动力学半径。此外,我们还发现M* 与BM型的关联很弱,使得后面的BM型团簇具有更亮的M*。发现红色和蓝色星系的M* 和半径之间的相关性,使得M* 向星系团中心衰减。

英文摘要:

We present the results from a survey of 57 low-redshift Abell galaxy clusters to study the radial dependence of the luminosity function (LF). The dynamical radius of each cluster, r200, was estimated from the photometric measurement of cluster richness, Bgc. The shape of the LFs are found to correlate with radius such that the faint-end slope, alpha, is generally steeper on the cluster outskirts. The sum of two Schechter functions provides a more adequate fit to the composite LFs than a single Schechter function. LFs based on the selection of red and blue galaxies are bimodal in appearance. The red LFs are generally flat for -22 < M_Rc < -18, with a radius-dependent steepening of alpha for M_Rc > -18. The blue LFs contain a larger contribution from faint galaxies than the red LFs. The blue LFs have a rising faint-end component (alpha ~ -1.7) for M_Rc > -21, with a weaker dependence on radius than the red LFs. The dispersion of M* was determined to be 0.31 mag, which is comparable to the median measurement uncertainty of 0.38 mag. This suggests that the bright-end of the LF is universal in shape at the 0.3 mag level. We find that M* is not correlated with cluster richness when using a common dynamical radius. Also, we find that M* is weakly correlated with BM-type such that later BM-type clusters have a brighter M*. A correlation between M* and radius was found for the red and blue galaxies such that M* fades towards the cluster center.

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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