Talk at the XMM Conference, Granada, May 2008 "Accretion in the Collapsar. How Long Can be a Long GRB? "
•
The Nature of the Intranight Variability of Radio-Quiet Quasars
Poster from the XMM Conference in 2008.
•
Hydrodynamical Simulations of the AGN Central Engine in 3D
Poster from the XMM Conference in 2008.
•
Formation and evolution of a torus in 3D
Movie 1...
The movie shows the formation of a 3D toroidal
structure around the accreting black hole (purely hydrodynamic case).
After initial stage of a
purely spherical, Bondi accretion, the rotationally supported torus is formed.
The isosurfaces shown by 3 different colors denote the constant density
regions (in cgs units).
In the innermost regions, the velocity of the gas is supersonic,
and instabilities arise. Finally, the structure gets tilted with respect to
the equator, and starts precessing.
Movie 2...
The movie shows the case of the
case of non-axisymmetric initial conditions: the rotating gas
is present not at every azimuth around the black hole, but
only in the region limited to delta(phi)=120o, and the closed, rotationally supported torus does not form.
Movie 3...
The same as above but for the initial condition of
delta(phi)=240o. The torus does not form and the flow
behaves chaotically.
Movie 4...
The same as above but for the initial condition of
delta(phi)=330o. In this case the torus forms, nevertheless
it is unstable and precesses.
Movie 5...
The isosurfaces of constant specific
(i.e. per unit mass)
angular momentum (in units of the critical angular momentum, lc=
2 Rgc). The simulation is made
for the axisymmetric initial conditions
(the same as in Movie 1).
Movie 6...
The isosurfaces of constant specific
angular momentum. The simulation is made
for the non-axisymmetric initial conditions with delta(phi)=330o
(as in Movie 4). The film shows how the material
with low and high angular momentum is mixing.
Evolution of density and velocity field in the central region, as shown in
the equatorial plane and azimuthal cuts at phi=0o and
180o
(simulation for delta(phi)=330o; as in Movie 4).
Seminar "Black hole accretion with low angular momentum",
CfA, 07/11/2007
•
How long can be a gamma ray burst?
Poster from the Nuclear Astrophysics Conference, Pasadena, July 2007
•
Instabilities in the hyperaccreting, neutrino-cooled disk in GRB
Poster from the Nuclear Astrophysics Conference, Pasadena, July 2007
