| The Massive Cluster Survey (MACS) is the first, large, X-ray selected sample of distant and X-ray luminous clusters; such objects being severely underrepresented in previous cluster surveys. A statistically robust, comprehensive study of the properties of these extreme systems is of paramount importance. This project is a study of the multi-wavelength properties of a statistical subsample of the 38 most distant (z ≥ 0.35) and luminous (LX > 5 x 1044 h-270 erg s-1, 0.1--2.4 keV) clusters from the MACS catalog.;Using optical imaging, multi-object optical spectroscopy; and detailed Chandra X-ray imaging, we investigate the properties, spatial distributions, and interactions of the two main baryonic cluster components (component galaxies and intracluster gas). We use a variety of substructure tests, including one-, two-, and three-dimensional galaxy distribution statistics and X-ray moment analysis, to determine morphologically disturbed clusters. Using this information we investigate the physical implications of the LX-- kT-sigma cluster scaling relations and the influence of morphology on the scatter and derived slopes. We also use this sample to explore the differences between virial and X-ray mass estimates.;Complementing the statistical investigation, we have conducted an in-depth study of the most disturbed system in our sample, MACSJ0717.5+3745. Through extensive large-scale multi-object spectroscopy and deep optical and X-ray imaging, we have characterized the current state of this system which is undergoing a substantial merger event. These observations lend strong support to a picture in which massive clusters grow via discrete as well as continuous infall of matter along large-scale filaments. |
