Debra Meloy Elmegreen, Bruce G. Elmegreen
Astrophysical Journal Letters
Spiral structure in disk galaxies is modeled with nine collisionless N-body simulations including live disks, halos, and bulges with a range of masses. Two of these simulations make long-lasting and strong two-arm spiral wave modes that last for ∼5 Gyr with constant pattern speed. These two had a light stellar disk and the largest values of the Toomre Q parameter in the inner region at the time the spirals formed, suggesting the presence of a Q-barrier to wave propagation resulting from the bulge. The relative bulge mass in these cases is about 10%. Models with weak two-arm spirals had pattern speeds that followed the radial dependence of the Inner Lindblad Resonance.
Debra Meloy Elmegreen, Bruce G. Elmegreen
Astrophysical Journal Letters
Kathryn Grasha, Bruce G. Elmegreen, et al.
ApJ
Yuri N. Efremov, Bruce G. Elmegreen, et al.
Astrophysical Journal
Bruce G. Elmegreen, Debra Meloy Elmegreen, et al.
Astrophysical Journal