Speaker
Description
I will present a numerical study of the dynamics of massive particles orbiting black holes and naked singularities in the Reissner-Nordström geometry. I modeled a stream of particles with a constant angular momentum and with a range of energies. I then solved the geodesic equation of motion and compared the trajectories around black holes and naked singularities by tuning the charge parameter of the metric. The setup that I used can approximate astrophysical scenarios such as tidal disruption events. I will discuss differences and similarities in the orbital dynamics and deflection angles. I found that particles reflected by a black hole follow a stream-like family of orbits within a narrow range of deflection angles, whereas in the case of naked singularities, particles are scattered in all directions on the plane of motion. I will explain this behavior as an interplay between the presence of a centrifugal barrier at the location of the unstable circular orbit and an absorbing event horizon in the case of a black hole or a reflective zero-gravity sphere in the case of a naked singularity. These qualitative differences are expected to impact the observable signatures of tidal disruption events.