Abstract
Clusters and superclusters of galaxies offer the ideal testing ground with which to investigate the effects of environment on galaxy evolution. With the combination of wide-field weak gravitational lensing studies and multi-band photometric observations, we are able to link distributions of dark and luminous matter and ask: how do galaxy properties correlate with environment? Using deep R-band imaging of the Abell 901/902 supercluster from the COMBO-17 survey, we apply weak lensing techniques to reveal the dark matter distribution, including three galaxy clusters at z ~ 0.17 and inter-cluster filamentary structure. We then use the photometric redshifts and spectral classifications resulting from the unique 17-band survey to produce a 3-D view of the luminous foreground structure and to trace galaxy types and properties as a function of their location in the underlying density field. We find strong evidence for segregation by type, with the highest density regions populated almost exclusively by galaxies classified as early-types. We also observe a critical surface mass density above which star-formation activity is truncated.
