Subaru Weak-Lensing Survey II: Multi-Object Spectroscopy and Cluster Masses
Subaru Weak-Lensing Survey II: Multi-Object Spectroscopy and Cluster Masses
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DOI：
10.1093/pasj/61.4.833
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发表时间：
2008-08
影响因子：
2.3
通讯作者：
T. Hamana;S. Miyazaki;N. Kashikawa;R. Ellis;R. Massey;A. Réfrégier;James E. Taylor
中科院分区：
文献类型：
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作者：
T. Hamana;S. Miyazaki;N. Kashikawa;R. Ellis;R. Massey;A. Réfrégier;James E. Taylor
我们提出的第一个结果的多对象光谱运动，以跟进通过弱透镜定位的集群候选人。我们的主要目标是寻找星系的空间浓度，这是合理的光学对应的弱透镜信号，并确定从成员星系的星系团红移。在36个目标星团候选者中的每一个周围，我们获得了15-32个星系红移。对于其中的28个目标，我们确认了一个安全的星系团识别，在± 3000 km s^（-1）的速度范围内有超过5个光谱星系。这包括三种情况，即两个不同红移的星系团沿沿着同一视线投射。在8个未经证实的目标中，有6个在不同的红移下发现了多个小星系的聚集，每个聚集至少包含三个光谱星系。因此，这些系统周围的弱透镜信号可能是由沿着同一视线投射的群体或小集群造成的。在剩下的两个目标中，都发现了一个小星系集中。在一些候选的超星系团系统中，我们发现了连接主密度峰和附近其他结构的细丝的额外证据。对于我们测量得最干净的星系团的一个子样本，我们研究了它们的弱透镜质量（M_（NFW），σ_（SIS））与其成员星系速度色散（σ_v）之间的统计关系，并与文献中光学和X射线选择的样本进行了比较。我们的透镜选择团簇符合σ_v = σ_（SIS），具有与光学和X射线选择团簇相似的散射。我们还导出了星系团质量与星系速度色散之间的经验关系式M_（200）E（z）= 11.0 × 10^（14）×（σ_v/1000 km s^（-1））^（3.0）h^（-1）M_（？），这与ΛCDM宇宙学中N体模拟的预言是一致的。
We present the first results of a multi-object spectroscopic campaign to follow up cluster candidates located via weak lensing. Our main goals are to search for spatial concentrations of galaxies that are plausible optical counterparts of the weak-lensing signals, and to determine the cluster redshifts from those of member galaxies. Around each of 36 targeted cluster candidates, we obtained 15–32 galaxy redshifts. For 28 of these targets, we confirmed a secure cluster identification, with more than five spectroscopic galaxies within a velocity of ±3000km s^(-1). This includes three cases where two clusters at different redshifts are projected along the same line-of-sight. In 6 of the 8 unconfirmed targets, we found multiple small galaxy concentrations at different redshifts, each containing at least three spectroscopic galaxies. The weak-lensing signal around those systems was thus probably created by the projection of groups or small clusters along the same line-of-sight. In both of the remaining two targets, a single small galaxy concentration was found. In some candidate super-cluster systems, we found additional evidence of filaments connecting the main density peak to an additional nearby structure. For a subsample of our most cleanly measured clusters, we investigated the statistical relation between their weak-lensing mass (M_(NFW), σ_(SIS)) and the velocity dispersion of their member galaxies (σ_ν), comparing our sample with optically and X-ray selected samples from the literature. Our lensing-selected clusters are consistent with σ_ν = σ_(SIS), with a similar scatter to that of optically and X-ray selected clusters. We also derived an empirical relation between the cluster mass and the galaxy velocity dispersion, M_(200)E(z) = 11.0 x 10^(14) x (σ_ν/1000km s^(-1))^(3.0) h^(-1)M_⊙, which is in reasonable agreement with predictions of N-body simulations in the ΛCDM cosmology.