MC2: GALAXY IMAGING AND REDSHIFT ANALYSIS OF THE MERGING CLUSTER CIZA J2242.8+5301
MC2: GALAXY IMAGING AND REDSHIFT ANALYSIS OF THE MERGING CLUSTER CIZA J2242.8+5301
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MC2：合并星团 CIZA J2242.8 5301 的星系成像和红移分析
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
R. Weeren
中科院分区：
文献类型：
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作者：
W. Dawson;M. J. Jee;A. Stroe;Y. K. Ng;N. Golovich;D. Wittman;D. Sobral;D. Sobral;M. Brüggen;H. Röttgering;R. Weeren
CIZA J2242.8+5301的X射线和射电观测表明这是一次主要的星团合并。尽管在 X 射线和射电方面进行了深入研究，但从星系群推断出的星团结构和动力学却鲜有报道。我们使用 Subaru SuprimeCam（g 和 i 波段）和加拿大-法国-夏威夷望远镜（r 波段）对该系统进行了深度 ( i < 25 ?> ) 宽带成像调查，并使用 Keck 深度成像多目标光谱仪对星团区域（505 红移）进行了全面的光谱调查。我们使用这些数据对系统进行全面的星系/红移分析，这是正确理解合并的几何形状和动力学以及使用合并来约束自相互作用暗物质的第一步。我们发现该系统主要由两个丰富度相当的子星团主导，预计分离度为 6 &farcm; 9 − 0.5 + 0.7 ?> (1.3 − 0.10 + 0.13 Mpc ?> )。我们发现南北子星团有相似的红移 z ≈ 0.188 ?> ，相对视距 (LOS) 速度差为 69 ± 190 km s − 1 ?> 。我们还发现南北子团的速度弥散分别为 1160 − 90 + 100 ?> 和 1080 − 70 + 100 km s − 1 ?> 。它们分别对应于质量 16.1 − 3.3 + 4.6 × 10 14 ?> 和 13.0 − 2.5 + 4.0 × 10 14 ?> M ☉ ?> 。虽然合并星团的速度色散测量可能存在偏差，但我们认为由于较大的预计分离距离和接近天空平面的合并配置，该系统中的偏差很小。我们还发现，北部和南部子团的 cD 在投影（分别为 55 和 85 kpc）和归一化 LOS 速度（北部和南部分别为 ∣ Δ v ∣ / &sgr; v = 0.43 ± 0.13 ?> 和 0.21 ± 0.12）方面都非常接近其子团中心。 CIZA J2242.8+5301是一种相对干净的解离团簇并合，其质量比接近1:1，这使其成为研究与并合相关的物理现象的理想并合。
X-ray and radio observations of CIZA J2242.8+5301 suggest that it is a major cluster merger. Despite being well studied in the X-ray and radio, little has been presented on the cluster structure and dynamics inferred from its galaxy population. We carried out a deep ( i < 25 ?> ) broadband imaging survey of the system with Subaru SuprimeCam (g and i bands) and the Canada–France–Hawaii Telescope (r band), as well as a comprehensive spectroscopic survey of the cluster area (505 redshifts) using Keck DEep Imaging Multi-Object Spectrograph. We use these data to perform a comprehensive galaxy/redshift analysis of the system, which is the first step to a proper understanding of the geometry and dynamics of the merger, as well as using the merger to constrain self-interacting dark matter. We find that the system is dominated by two subclusters of comparable richness with a projected separation of 6 &farcm; 9 − 0.5 + 0.7 ?> (1.3 − 0.10 + 0.13 Mpc ?> ). We find that the north and south subclusters have similar redshifts of z ≈ 0.188 ?> with a relative line-of-sight (LOS) velocity difference of 69 ± 190 km s − 1 ?> . We also find that north and south subclusters have velocity dispersions of 1160 − 90 + 100 ?> and 1080 − 70 + 100 km s − 1 ?> , respectively. These correspond to masses of 16.1 − 3.3 + 4.6 × 10 14 ?> and 13.0 − 2.5 + 4.0 × 10 14 ?> M ☉ ?> , respectively. While velocity dispersion measurements of merging clusters can be biased, we believe the bias in this system to be minor due to the large projected separation and nearly plane-of-sky merger configuration. We also find that the cDs of the north and south subclusters are very near their subcluster centers, in both projection (55 and 85 kpc, respectively) and normalized LOS velocity ( ∣ Δ v ∣ / &sgr; v = 0.43 ± 0.13 ?> and 0.21 ± 0.12 for the north and south, respectively). CIZA J2242.8+5301 is a relatively clean dissociative cluster merger with near 1:1 mass ratio, which makes it an ideal merger for studying merger-associated physical phenomena.