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arXiv 0911.3740astro-ph.CO
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VIMOS VLT深度调查:小组目录

The VIMOS VLT Deep Survey: the group catalogue

O. Cucciati, C. Marinoni, A. Iovino, S. Bardelli, C. Adami, A. Mazure, M. Scodeggio, D. Maccagni, S. Temporin, E. Zucca, G. De Lucia, J. Blaizot, B. Garilli, B.… 展开作者

O. Cucciati, C. Marinoni, A. Iovino, S. Bardelli, C. Adami, A. Mazure, M. Scodeggio, D. Maccagni, S. Temporin, E. Zucca, G. De Lucia, J. Blaizot, B. Garilli, B. Meneux, G. Zamorani, O. Le Fèvre, A. Cappi, L. Guzzo, D. Bottini, V. Le Brun, L. Tresse, G. Vettolani, A. Zanichelli, S. Arnouts, M. Bolzonella, S. Charlot, P. Ciliegi, T. Contini, S. Foucaud, P. Franzetti, I. Gavignaud, O. Ilbert, F. Lamareille, H. J. McCracken, B. Marano, R. Merighi, S. Paltani, R. Pellò, A. Pollo, L. Pozzetti, D. Vergani, E. Pérez-Montero

摘要:

[摘要]我们提出了一个均匀的和完整的目录中确定的光学集团在纯粹的通量限制(17.5<=I<=24.0)VIMOS-VLT深调查(VVDS)。我们使用从MILLENNIUM模拟中提取的模拟目录,以纠正可能影响整体分布以及所识别系统的个体属性的潜在系统学。模拟样本使我们能够预测的数量和属性的群体,可以潜在地发现在一个调查与VVDS样的选择功能。我们用它们来纠正预期的不完整性,并评估如何以及星系红移跟踪视线的速度分散的基础质量过密度。特别是,我们训练这些模拟目录采用组发现技术(沃罗诺伊-德劳内方法,VDM)。其目标是微调其自由参数,以稳健和无偏的方式恢复群的红移和速度色散分布,并最大限度地提高群目录的完整性(C)和纯度(P)。我们确定了318个VVDS群,其中至少有2个成员在0.2 ≤ z ≤ 1.0范围内,其中144(/30)个至少有3(/5)个成员。样本总体C=60%,P= 50%。如果我们使用最大化P(75%)的参数集运行算法,则至少有3个成员的近45%的组仍然可以恢复。我们利用群样本研究了蓝星系(U-B<=1)在0.2 ≤ z ≤ 1范围内fb的红移演化。我们发现,无论星系所处的环境如何,星系群中的f_b都明显低于星系系综中的f_b。这些量随着红移而增加,在组中f_b表现出略微显著的陡峭增加。我们还证实,在任何探索的红移,f_b减少,增加集团丰富度,我们向更暗的亮度扩展的幅度范围内,这一结果成立。

英文摘要:

[Abridged] We present a homogeneous and complete catalogue of optical groups identified in the purely flux limited (17.5<=I<=24.0) VIMOS-VLT Deep Survey (VVDS). We use mock catalogues extracted from the MILLENNIUM simulation, to correct for potential systematics that might affect the overall distribution as well as the individual properties of the identified systems. Simulated samples allow us to forecast the number and properties of groups that can be potentially found in a survey with VVDS-like selection functions. We use them to correct for the expected incompleteness and also to asses how well galaxy redshifts trace the line-of-sight velocity dispersion of the underlying mass overdensity. In particular, we train on these mock catalogues the adopted group-finding technique (the Voronoi-Delaunay Method, VDM). The goal is to fine-tune its free parameters, recover in a robust and unbiased way the redshift and velocity dispersion distributions of groups and maximize the level of completeness (C) and purity (P) of the group catalogue. We identify 318 VVDS groups with at least 2 members within 0.2<=z<=1.0, among which 144 (/30) with at least 3 (/5) members. The sample has globally C=60% and P=50%. Nearly 45% of the groups with at least 3 members are still recovered if we run the algorithm with a parameter set which maximizes P (75%). We exploit the group sample to study the redshift evolution of the fraction f_b of blue galaxies (U-B<=1) within 0.2<=z<=1. We find that f_b is significantly lower in groups than in the whole ensemble of galaxies irrespectively of their environment. These quantities increase with redshift, with f_b in groups showing a marginally significant steeper increase. We also confirm that, at any explored redshift, f_b decreases for increasing group richness, and we extend towards fainter luminosities the magnitude range over which this result holds.

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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