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Investigating the Long-term Evolution of Galaxies: Noise, Cuspy Halos and Bars
Astronomy Department Faculty Publication Series
  • Martin D. Weinberg, University of Massachusetts - Amherst
Publication Date
This paper was harvested from and ArXiv identifier is arXiv:0110700v1

I review the arguments for the importance of halo structure in driving galaxy evolution and coupling a galaxy to its environment. We begin with a general discussion of the key dynamics and examples of structure dominated by modes. We find that simulations with large numbers of particles (N ≥ 106) are required to resolve the dynamics. Finally, I will describe some new results which demonstrates that a disk bar can produce cores in a cuspy CDM dark-matter profile within a gigayear. An inner Lindblad-like resonance couples the rotating bar to halo orbits at all radii through the cusp, rapidly flattening it. This resonance disappears for profiles with cores and is responsible for a qualitative difference in bar-driven halo evolution with and without a cusp. Although the bar gives up the angular momentum in its pattern to make the core, the formation epoch is rich in accretion events to recreate or trigger a classic stellar bar. The evolution of the cuspy inner halo by the first-generation bar paves the way for a long-lived subsequent bar with low torque and a stable pattern speed.

Citation Information
Martin D. Weinberg. "Investigating the Long-term Evolution of Galaxies: Noise, Cuspy Halos and Bars" (2001)
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