LoCuSS: weak-lensing mass calibration of galaxy clusters
LoCuSS: weak-lensing mass calibration of galaxy clusters
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DOI：
10.1093/mnras/stw1539
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发表时间：
2015-07
影响因子：
4.8
通讯作者：
N. Okabe;Graham P. Smith
中科院分区：
文献类型：
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作者：
N. Okabe;Graham P. Smith
基于安装在8.2米斯巴鲁望远镜上的SuPrime-Cam的均匀高质量观测，我们给出了50个X射线发光星系团的弱透镜质量测量结果。我们密切关注可能出现的系统性偏差，目标是将其控制在$\LE4$%的水平。在弱透镜测量单个星系团的质量时，系统偏差的主要来源是微弱星系团和前景星系对背景星系表的污染。我们扩展了我们的选择背景星系的保守方法，选择比星系团成员的红色序列更红的$(V-I‘)$背景星系，以使用依赖于星系团中心半径的颜色切割。这使我们能够定义遭受$\LE1%污染的背景星系样本，并包含每平方角分钟$13$星系。由于我们背景星系目录的纯洁性，我们在分析中发现的最大系统是形状测量偏差3$%，我们使用模拟探测弱切变高达$g=0.3$进行测量。我们的单个星团质量和浓度测量结果与质量-浓度关系的预测非常一致。同样，我们的堆叠剪切剖面与Navarro Frenk and White剖面非常吻合。我们新的LoCuSS质量测量与CCCP和Clash调查一致，并与巨人队的称重在$\sim1-2\sigma$意义上保持紧张关系。总体而言，从这些互补性调查中得出的0.3美元的共识代表着星团质量校准的重要进展，对星团宇宙学来说是个好兆头。
We present weak-lensing mass measurements of 50 X-ray luminous galaxy clusters at $0.15\le z\le0.3$, based on uniform high quality observations with Suprime-Cam mounted on the 8.2-m Subaru telescope. We pay close attention to possible systematic biases, aiming to control them at the $\le4$ per cent level. The dominant source of systematic bias in weak-lensing measurements of the mass of individual galaxy clusters is contamination of background galaxy catalogues by faint cluster and foreground galaxies. We extend our conservative method for selecting background galaxies with $(V-i')$ colours redder than the red sequence of cluster members to use a colour-cut that depends on cluster-centric radius. This allows us to define background galaxy samples that suffer $\le1$ per cent contamination, and comprise $13$ galaxies per square arcminute. Thanks to the purity of our background galaxy catalogue, the largest systematic that we identify in our analysis is a shape measurement bias of $3$ per cent, that we measure using simulations that probe weak shears upto $g=0.3$. Our individual cluster mass and concentration measurements are in excellent agreement with predictions of the mass-concentration relation. Equally, our stacked shear profile is in excellent agreement with the Navarro Frenk and White profile. Our new LoCuSS mass measurements are consistent with the CCCP and CLASH surveys, and in tension with the Weighing the Giants at $\sim1-2\sigma$ significance. Overall, the consensus at $z\le0.3$ that is emerging from these complementary surveys represents important progress for cluster mass calibration, and augurs well for cluster cosmology.