New X-ray Clusters in the EMSS II: Optical Properties
Abstract
We present optical images for 9 new clusters of galaxies we have found in a reanalysis of the Einstein IPC images comprising the Extended Medium Sensitivity Survey (EMSS). Based on the presence of a red sequence of galaxies in a color-magnitude (CM) diagram, a redshift is estimated for each cluster. Galaxy overdensities (cluster richnesses) are measured in each field using the B_gc statistic which allows their plausible identification with the X-ray emission. The nature of our X-ray detection algorithm suggests that most of these clusters have low X-ray surface brightness (LSB) compared to the previously known EMSS clusters. We compare the optical and X-ray observations of these clusters with the well-studied Canadian Network for Observational Cosmology (CNOC) subsample of the EMSS, and conclude that the new clusters exhibit a similar range of optical richnesses, X-ray luminosities, and, somewhat surprisingly, galaxy populations as the predominantly rich, relaxed EMSS/CNOC clusters.
Keywords
Cite
@article{arxiv.astro-ph/0110284,
title = {New X-ray Clusters in the EMSS II: Optical Properties},
author = {Aaron D. Lewis and E. Ellingson and John T. Stocke},
journal= {arXiv preprint arXiv:astro-ph/0110284},
year = {2009}
}
Comments
Accepted to ApJ, 17 pages, 14 figures, uses emulateapj5.sty