Visualization of Cold + Hot and Cold Dark Matter Cosmologies versus CfA1 Data

We use state-of-the-art scientific visualization techniques to explore cold + hot (CHDM) and cold dark matter (CDM) cosmologies and to contrast them to each other (in real and redshift space) and to the CfA1 data (in redshift space). We show dark matter halo locations and particle distributions at the present epoch, using animations and lighting or cutting planes to show three-dimensional structure; we also show isodensity contours for both cold and hot particles in one of the CHDM simulations and halo minimal spanning trees corresponding to halo grouping. Presenting the data visually provides valuable insights that can enhance analyses. Visually, CHDM exhibits considerable more filamentary structure and larger voids compared to CDM. Included in the accompanying videotape is an animation of the surprisingly rich dark matter substructure we discovered in the CHDM simulations.