Effects of the rotation of the central black hole in a disk galaxy model

The orbital properties of stars moving on the (R, z) plane of a disk galaxy with a central rotating black hole are numerically investigated. For modeling the dynamical system, we use a pseudo-Newtonian potential that can replicate specific physical properties of a rotating distribution of matter, such as the position of the marginally bound orbit and the radius of the last stable orbit for the Kerr metric. Massive sets of starting conditions are classified for determining the dynamics of the test particle’s trajectories. Specifically, we manage not only to distinguish regular, chaotic, and collisional motion but also categorize all regular trajectories into regular families. The orbit taxonomy suggests that the angular momentum of the central black hole has a profound influence on the orbital properties of the galaxy. In particular, we find that stars having energies that correspond to motion relatively close to the black hole are highly affected by its rotation, while stars moving at large galactocentric distances are less influenced by the same parameter. In addition, it is numerically demonstrated that the appearance of certain resonant orbits is due to the rotation of the central black hole.