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arXiv 0910.4358astro-ph.CO
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K2:一种基于CFHTLS图像的星系团探测新方法

K2: A new method for the detection of galaxy clusters based on CFHTLS multicolor images

Karun Thanjavur, Jon Willis, David Crampton

摘要:

我们已经开发了一种新的方法,K2,优化的星系团的探测在银河系图像。基于红色序列方法,K2使用颜色和位置的同时增强来检测聚类。通过广泛的蒙特卡罗模拟和通过比较现有的集群目录的基础上两种不同的光学方法,也对X射线数据的检测意义是鲁棒的确定。K2还提供了候选星系团的丰度和光度红移的定量估计。最初,K2被应用于CFHTLS-Wide数据的161平方度的双色gri图像。我们的模拟表明,在我们选择的阈值下,错误检测率仅为~ 1%,并且对于类天炉座和更丰富的星系团,在红移为0.6时,星系团目录完成了~80%,对于较差的星系团,红移为z ~0.3。基于Terapix T05发布的GRI光度星表,每平方度探测到35个星团,每两平方度有1-2个类似天炉座或更丰富的星团。包含6144个星系团数据的星表已经准备好,其中239个是富星系团。这些星系团,尤其是后者,正在寻找引力透镜--这是我们在CFHTLS中进行星系团检测的主要动机之一。K2方法可以很容易地扩展到使用额外的颜色信息,从而提高整体集群检测到更高的红移。完整的K2星系团星表,以及成员星系的补充星表,可向作者索取。

英文摘要:

We have developed a new method, K2, optimized for the detection of galaxy clusters in multicolor images. Based on the Red Sequence approach, K2 detects clusters using simultaneous enhancements in both colors and position. The detection significance is robustly determined through extensive Monte-Carlo simulations and through comparison with available cluster catalogs based on two different optical methods, and also on X-ray data. K2 also provides quantitative estimates of the candidate clusters' richness and photometric redshifts. Initially K2 was applied to 161 sq deg of two color gri images of the CFHTLS-Wide data. Our simulations show that the false detection rate, at our selected threshold, is only ~1%, and that the cluster catalogs are ~80% complete up to a redshift of 0.6 for Fornax-like and richer clusters and to z ~0.3 for poorer clusters. Based on Terapix T05 release gri photometric catalogs, 35 clusters/sq deg are detected, with 1-2 Fornax-like or richer clusters every two square degrees. Catalogs containing data for 6144 galaxy clusters have been prepared, of which 239 are rich clusters. These clusters, especially the latter, are being searched for gravitational lenses -- one of our chief motivations for cluster detection in CFHTLS. The K2 method can be easily extended to use additional color information and thus improve overall cluster detection to higher redshifts. The complete set of K2 cluster catalogs, along with the supplementary catalogs for the member galaxies, are available on request from the authors.

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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