Ionized Keplerian Disks Demonstrating Interplay Between Strong Gravity and Magnetism

Using the dynamics of charged test particles, we study the interplay of extremely strong gravitational and magnetic fields acting on ionized Keplerian disks. We assume a Schwarzschild spacetime of mass <i>M</i> combined with a dipole magnetic field represented by a dimensionless parameter <i>b</i>, characterizing the influence of fields near the gravitational radius rg=2GM/c2. The particle dynamics can be realized in three regimes: gravitational (b≪1), magnetic (b≫1), and chaotic (b∼1). We demonstrate the ionization of disks that are originally both orthogonal and inclined to the magnetic field axis and consider both magnetic attraction and magnetic repulsion acting on the ionized particles. The case of secondary ionized equatorial charged disks is also discussed. The ionization in the dipole magnetic field is compared with the case of a Schwarzschild spacetime endowed with an asymptotically uniform magnetic field. The differences in the dipole and uniform fields are significant in the magnetic and chaotic regimes, while they are suppressed in the gravitational regime.