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arXiv 0809.4552astro-ph
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低红移EIS团簇IV的多目标光谱研究。z~0.3-0.4时匹配滤波器结果的可靠性

Multi-object spectroscopy of low-redshift EIS clusters IV. Reliability of matched-filter results at z~0.3-0.4

L. F. Grove, L. da Costa, C. Benoist

摘要:

本文给出了23个ESO成像巡天(EIS)星系团场中747个星系的新红移。我们使用的“差距”的技术,以寻找显着的超密度在红移空间识别组/星系团。通过这种方式,我们在23个簇候选场中的10个中光谱确认了匹配滤波器估计红移z_MF=0.3-0.4的系统,并且光谱红移在z=0.158到z=0.534的范围内。我们发现,本文所识别的系统具有较宽的一维速度频散(175-497 km/s)和丰富度(12 L *<=L<= 65 L *)范围。采样不足和子结构的污染都有助于这些测量的不确定性。通过对星系群颜色的分析,我们发现~60%的光谱学确认的系统具有与被动恒星演化模型颜色匹配的“显著”红色序列。利用这篇论文,我们完成了对58个红移z<=0.4的EIS星系团候选者的光谱测量。我们总共测量了1954个星系在z=0.0065到z=0.6706范围内的红移。在58个系统中,我们确认了42个(约75%)的红移在z=0.095和z=0.534之间。

英文摘要:

abridged) In this paper we present new redshifts for 747 galaxies in 23 ESO Imaging Survey (EIS) cluster fields. We use the "gap"-technique to search for significant overdensities in redshift space for identifying groups/clusters of galaxies. In this way we spectroscopically confirm systems in 10 of the 23 cluster candidate fields with a matched-filter estimated redshift z_MF=0.3-0.4 and with spectroscopic redshifts in the range from z=0.158 to z=0.534. We find that the systems identified in the present paper span a broad range of one-dimensional velocity dispersion (175-497 km/s) and richness (12L*<=L<=65L*). Both undersampling and contamination by substructures contribute to the uncertainty of these measurements. From the analysis of the colours of the galaxy populations we find that ~60% of the spectroscopically confirmed systems have a "significant" red sequence with a colour matching passive stellar evolution models. With this paper we complete our spectroscopic survey of the fields of 58 EIS cluster candidates with estimated redshifts z<=0.4. We have measured a total of 1954 galaxy redshifts in the range z=0.0065 to z=0.6706. Of the 58 systems we confirm 42 (~75%) with redshifts between z=0.095 and z=0.534.

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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