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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)
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)
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 present new calculations of X-ray polarization from black hole (BH) accretion disks in the thermally-dominated state, using a Monte-Carlo ray-tracing code in full general relativity. In contrast to many previously published studies , our approach allows us to include returning radiation that is deflected by the strong-field gravity of the BH and scatters(More)
Because the magnetorotational instability is capable of exponentially amplifying weak preexisting magnetic fields, it might be hoped that the character of the magnetic field in accretion disks would be independent of the nature of the seed field. However, the divergence-free nature of magnetic fields in highly conducting fluids ensures that their(More)
The X-ray spectra of accreting black hole systems generally contain components (sometimes dominating the total emission) which are well-fit by thermal Comptonization models with temperatures ∼ 100 keV. We demonstrate why, over many orders of magnitude in heating rate and seed photon supply, hot plasmas radiate primarily by inverse Compton scattering, and(More)
We calculate the efficiency of iron K line emission and iron K absorption in photoionized models using a new set of atomic data. These data are more comprehensive than those previously applied to the modeling of iron K lines from photoionized gases, and allow us to systematically examine the behavior of the properties of line emission and absorption as a(More)
We explore the thermodynamic and global structural properties of a local patch of an accretion disk whose parameters were chosen so that radiation pressure and gas pressure would be comparable in magnitude. Heating, radiative transport, and cooling are computed self-consistently with the structure by solving the equations of radiation MHD in the(More)