Movies & Images

Accretion disks

From Foucart, Chandra, Gammie, and Quataert (2015).

Evolution of a slowly accreting disk around a rapidly spinning black hole. The plasma forming these disks is nearly collisionless. Thus, instead of modeling the disk as an ideal fluid, we use an extended magnetohydrodynamics model including non-ideal effects such as heat conduction and shear viscosity. The movie shows the evolution of the density (left), heat flux (center) and anisotropy between the pressure along magnetic field lines and orthogonal to the field (right). The latter is proportional to the magnitude of the shear viscosity in our model. The simulation shows that the pressure anisotropy is comparable to the magnetic pressure, and thus that the viscous shear is of the same order as the magnetic shear tensor. The pressure anisotropy then has an O(1) effect on the evolution of the disk.

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Compact binary mergers

Merger of a black hole-neutron star binary for a relatively low mass black hole (3 neutron star masses).

The initial spin of the black hole is chosen to be misaligned with the orbital angular momentum of the binary by 80 degrees. This causes the orbital plane to precess as the inspiral proceeds.

Movie by Bryant Garcia (Cornell) - 2009

Disruption of a neutron star by a more massive (7 solar masses) rapidly rotating black hole. Part of the remaining material forms a hot, dense accretion disk. More than 5% of a solar mass is ejected from the system in a rapidly moving tidal tail. Image taken from this paper.

Energy density and energy flux of the neutrinos in the accretion disk resulting from a neutron star-black hole merger (from this paper). We show the energy density around the location at which the neutrinos are no longer trapped in the high density disk. Most of the emission comes from the hot inner regions of the disk, where general relativistic effects play an important role in determining the trajectories and energies of the neutrinos.