Speaker
Description
We present a model of a charged, barotropic, thick accretion disc around a Schwarzschild black hole. In this model, the electromagnetic field is entirely self-generated by the azimuthal current of the accreting fluid. The vector potential is modelled using a heuristic expression inspired by the leading-order multipolar expansion of a circular current loop. We obtain two-dimensional maps of the fluid density, effective potential and charge density, and compare them with their neutral counterparts. We demonstrate that introducing charge shifts the location of the innermost stable circular orbit, the cusp radius and the pressure maximum of the torus relative to the neutral configuration. The magnitude and direction of this displacement depend sensitively on the magnetic amplitude. The results of this initial study have motivated us to extend the model to include an external magnetic field superimposed on the self-generated field. We are currently developing also the interaction between internally and externally driven electromagnetic effects on the disk geometry and stability.