Canadian Astronomical Society (CASCA)
Société canadienne d'astronomie (CASCA)
John J. DUBINSKI
University of Toronto
A Universe in Motion : Dynamical Evolution of Galaxies in the New Cosmological Paradigm
Interactions and mergers drive galaxy morphological evolution. The galaxies that condense out of the cosmological expansion form in groups and fall into clusters creating opportunities for interactions. Interactions lead to enhanced rates of star formation and starbursts and ultimately lead to mergers - the main mode of formation of the elliptical galaxies. New software and parallel supercomputing hardware allow simulations of unprecedented resolution for both the formation of cosmological structure and the dynamics of galaxy interactions and mergers. The recent convergence of the cosmological paradigm the past few years allows a detailed quantitative examination of the dynamical evolution of galaxies in the cosmological context. Some key issues are understanding the merger rate and its importance for the development of the ellipticals and their scaling relations, the dependence on morphology on galactic environment and the formation of galaxy clusters, their giant central ellipticals and the recently discovered distribution of intracluster stars. Visualization and animation of these dynamical processes lead to new intuition and understanding that is not readily apparent in the still lifes of galaxies created by the world’s great telescopes. Animations of galaxy mergers reveal both grace and violence that creates a complex, distribution of shells, loops and ripples that lies just below the threshold of the deepest images. Simulations of clusters clearly demonstrate the formation of giant ellipticals and surrounding smaller ellipticals embedded in the spray of intracluster stars. I will illustrate these results with new animations that attempt to breathe life into the still lifes of nature.