We use the dense HectoMAP redshift survey to explore the properties of 104 redMaPPer cluster candidates. The redMaPPer systems in HectoMAP cover the full range of richness and redshift (0.08 <z< 0.60). Fifteen systems included in the Subaru/Hyper Suprime-Cam public data release are bona fide clusters. The median number of spectroscopic members per cluster is ∼20. We include redshifts of 3547 member candidates listed in the redMaPPer catalog whether they are cluster members or not. We evaluate the redMaPPer membership probability spectroscopically. The scaled richness ({\lambda}rich/S) provided by redMaPPer correlates tightly with the spectroscopic richness regardless of the cluster redshift and appears to be a better mass proxy than the original richness, {\lambda}rich. The purity (number of real systems) in redMaPPer exceeds 90% even at the lowest richness; however, there is some incompleteness. Five massive galaxy clusters (M ≳2×1013 M⊙) associated with X-ray emission in the HectoMAP region are missing from the catalog.
Cite
@article{arxiv.1712.00872,
title = {The HectoMAP Cluster Survey - I. redMaPPer Clusters},
author = {Jubee Sohn and Margaret J. Geller and Kenneth J. Rines and Ho Seong Hwang and Yousuke Utsumi and Antonaldo Diaferio},
journal= {arXiv preprint arXiv:1712.00872},
year = {2018}
}
Comments
submitted to ApJ, a revised version in response to the referee's comments, 15 pages, 14 figures, 3 tables; data will be available when the paper is accepted