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“Using Numerical Simulations to Study the Formation and Evolution of Galaxies” Dr. TJ Cox Harvard/Smithsonian CfA |
| The past decade has produced an amazingly robust picture for the universe we live in. We now know that the universe is composed primarily of (cold) dark matter and an unknown dark energy. This model predicts that structure forms hierarchically, i.e., small objects collapse at early times and grow via mergers and gravity. The prevailing idea for the formation of galactic structure is that the properties we observe are a direct byproduct of this hierarchical merger history, however, a detailed mapping between specific merger histories, and the wide variety of galaxy types is still uncertain. By using a comprehensive set of state-of-the-art numerical simulations, we show how this process is being studied, and what some of the common scenarios might be. For example, we show that a single disk-disk merger, such as that which will occur in 5 Gyr between our own Milky Way and our nearest neighbor Andromeda, is a plausible mechanism to form many elliptical galaxies provided that dissipation is involved. We also show where this picture fails, and outline how current and future work will address these shortcomings and yield testable predictions of the model. |