2003/01/01 by Weinberg, Weinberg, MD
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Astronomy #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies
paper · doi:10.7275/2683
openalex publication_date 2003/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/01
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.