The HectoMAP Cluster Survey. II. X-Ray Clusters

Abstract

We apply a friends-of-friends algorithm to the HectoMAP redshift survey and cross-identify associated X-ray emission in the ROSAT All-Sky Survey data (RASS). The resulting flux-limited catalog of X-ray cluster surveys is complete to a limiting flux of similar to 3 x 10(-13) erg s(-1) cm(-2) and includes 15 clusters (7 newly discovered) with redshifts z <= 0.4. HectoMAP is a dense survey (similar to 1200 galaxies deg(-2)) that provides similar to 50 members (median) in each X-ray cluster. We provide redshifts for the 1036 cluster members. Subaru/Hyper Suprime-Cam imaging covers three of the X-ray systems and confirms that they are impressive clusters. The HectoMAP X-ray clusters have an L-X-sigma(cl) scaling relation similar to that of known massive X-ray clusters. The HectoMAP X-ray cluster sample predicts similar to 12,000 +/- 3000 detectable X-ray clusters in RASS to the limiting flux, comparable with previous estimates.