Julian Krolik

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Most streamline generation algorithms either provide a particular density of streamlines across the domain or explicitly detect features, such as critical points, and follow customized rules to emphasize those features. However, the former generally includes many redundant streamlines, and the latter requires Boolean decisions on which points are features(More)
We compute a series of three-dimensional general relativistic magnetohydrodynamic simulations of accretion flows in the Kerr metric to investigate the properties of the unbound outflows that result. The overall strength of these outflows increases sharply with increasing black hole rotation rate, but a number of generic features are found in all cases. The(More)
Magnetic connections to the plunging region can exert stresses on the inner edge of an accretion disk around a black hole. We recompute the relativistic corrections to the thin-disk dynamics equations when these stresses take the form of a time-steady torque on the inner edge of the disk. The additional dissipation associated with these stresses is(More)
We have carried out fully relativistic numerical simulations of accretion disks in the Kerr metric. In this paper we focus on the unbound outflows that emerge self-consistently from the accretion flow. These outflows are found in the axial funnel region and consist of two components: a hot, fast, tenuous outflow in the axial funnel proper, and a colder,(More)
We present a detailed analysis of the magnetic field structure found in a set of four general relativistic 3D MHD simulations of accreting tori in the Kerr metric with different black hole spins. Among the properties analyzed are the field strength as a function of position and black hole spin, the shapes of field lines, the degree to which they connect(More)
We use a relativistic ray-tracing code to calculate the light curves observed from a global general relativistic magneto-hydrodynamic simulation of an accretion flow onto a Schwarzschild black hole. We apply three basic emission models to sample different properties of the time-dependent accretion disk. With one of these models, which assumes thermal(More)
This is the first in a series of papers that investigate the properties of accretion flows in the Kerr metric through three-dimensional, general relativistic magnetohydrodynamic simulations of tori with a near-Keplerian initial angular velocity profile. We study four models with increasing black hole spin, from a/M = 0 to 0.998, for which the structural(More)
Accreting black holes radiate in one of several spectral states, switching from one to another for reasons that are as yet not understood. Using the best studied example, Cyg X-1, we identify the geometry and physical conditions characterizing these states. In particular, we show that in the hard state most of the accretion energy is dissipated in a(More)
Numerical simulation of magnetohydrodynamic (MHD) turbulence makes it possible to study accretion dynamics in detail. However, special effort is required to connect inflow dynamics (dependent largely on angular momentum transport) to radiation (dependent largely on thermodynamics and photon diffusion). To this end, we extend the flux-conservative, general(More)