Dynamics of Plasma Close to the Horizon of a Schwarzschild Black Hole

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Abstract
General relativistic plasma dynamics relevant to the condition very close to a black hole event horizon is developed. The plasma is studied using the 3+1 paradigm of general relativistic magnetohydrodynamics. The equilibrium and dynamical solution of such a plasma in Rindler's coordinates are presented. We assume a pressure source at the horizon that provides the balancing force to stop the radial infall of the plasma. We show that the plasma near the black hole is subject to the convective instability when the magnetic field is absent and to the magnetic buoyancy instability when a toroidal field exists. These instabilities are largely suppressed, however, in the presence of a poloidal magnetic field. Therefore, when a poloidal magnetic field is twisted and changed into a toroidal field by plasma rotation, the plasma is destabilized due to these instabilities. The manifestation of these instabilities is a jet formation from this inner region of a black hole atmosphere. Since this formation mechanism is deep in the gravitational potential of a black hole, the energy liberated and the jet formed by this mechanism can be very substantial. We suggest that this mechanism provides a viable model for recent observations of the superluminal jets from the galactic black hole candidates GRS 1915+105 and GRO J1655-40.