Dynamical structures of the Milky-Way disk
speaker: Michiko Fujii
Abstract:
Gaia, an astrometry satellite, has dramatically updated the dynamical structures of the Milky-Way galaxies. However, the information that we can obtain from observations is limited in terms of both time and space. We can observe only the current positions and velocities of stars within a few kpc from the Sun. On the other hand, simulations provide us the entire time evolution of modeled galaxies.
We performed fully self-consistent N-body simulations of disk galaxies modeling the Milky Way. We model galactic disk, bulge, and dark matter halo as N-body systems with a maximum of 8 billion particles using the same mass resolution to avoid numerical heating. Our high-resolution simulation allows us to follow the individual orbits of stars trapped in the bar’s inner Lindblad resonances. Such resonant orbits explain observed structures in the distribution of stars in the phase space. I will also talk about the transient spiral structures of disk galaxies.