Weak-lensing clusters from HSC survey first-year data: Mitigating the dilution effect of foreground and cluster-member galaxies
Weak-lensing clusters from HSC survey first-year data: Mitigating the dilution effect of foreground and cluster-member galaxies
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DOI：
10.1093/pasj/psaa068
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发表时间：
2020-04
期刊：
影响因子：
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通讯作者：
T. Hamana;M. Shirasaki;Yen-Ting Lin
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文献类型：
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作者：
T. Hamana;M. Shirasaki;Yen-Ting Lin
我们提出了一个弱透镜集群搜索使用超优凸轮斯巴鲁战略计划（HSC调查）第一年的数据。我们特别关注星系团成员和前景星系对星系团微弱透镜信号的稀释效应；我们采用受星系团成员星系影响最小的全局归一化弱透镜估计量，并利用光度红移信息选择源星系以减轻前景星系的影响。我们产生了六个具有不同低$z$星系切割的源星系样本，为每个源样本构建了弱透镜质量图，并在质量图中搜索覆盖$\sim$120°$^2$有效调查区域的峰值。我们将六个高峰目录合并为包含124个信噪比大于5的高峰的候选聚类样本。我们将峰值样本与基于相同HSC调查数据构建的公共光学星团目录进行交叉匹配，以识别峰值对应的星团。我们发现124个峰中有107个在距离峰位5 arcmin内匹配簇。其中，我们定义了64个安全聚类的子样本，我们使用它来检查弱透镜聚类搜索中的稀释效应。我们发现具有低z$星系切割的源样本减轻了对高z$星团（$z > 0.3$）弱透镜信号的稀释效应，从而结合来自不同源样本的多个峰表提高了弱透镜星团搜索的效率。
We present a weak lensing cluster search using Hyper Suprime-Cam Subaru Strategic Program (HSC survey) first-year data. We pay special attention to the dilution effect of cluster member and foreground galaxies on weak lensing signals from clusters of galaxies; we adopt the globally normalized weak lensing estimator which is least affected by cluster member galaxies, and we select source galaxies by using photometric redshift information to mitigate the effect of foreground galaxies. We produce six samples of source galaxies with different low-$z$ galaxy cuts, construct weak lensing mass maps for each of the source sample, and search for high peaks in the mass maps that cover an effective survey area of $\sim$120 deg$^2$. We combine six catalogs of high peaks into a sample of cluster candidates which contains 124 high peaks with signal-to-noise ratios greater than five. We cross-match the peak sample with the public optical cluster catalog constructed from the same HSC survey data to identify cluster counterparts of the peaks. We find that 107 out of 124 peaks have matched clusters within 5 arcmin from peak positions. Among them, we define a sub-sample of 64 secure clusters that we use to examine dilution effects on our weak lensing cluster search. We find that source samples with the low-$z$ galaxy cuts mitigate the dilution effect on weak lensing signals of high-$z$ clusters ($z > 0.3$), and thus combining multiple peak catalogs from different source samples improves the efficiency of weak lensing cluster searches.