Speaker
Description
Black hole X-ray binaries (BHXRBs) and Active Galactic Nuclei (AGN)
transition through a series of accretion states in a well-defined order.
The accretion states, each associated with different luminosities,
spectral and variability characteristics, quasi periodic oscillations
(QPOs) and outflow properties, are thought to be triggered by physical
changes in the accretion disk around the central black hole.The
mechanisms behind state transitions, the geometry of transitional disks
and the physical mechanisms driving the emission characteristics we
observe remain highly debated.
General relativistic magneto-hydrodynamic simulations (GRMHD) are
increasingly providing crucial insights into the accretion process, the
launch of outflows and the physical processes driving state transitions
in BHXRBs and AGN. Using GRMHD simulations conducted with the H-AMR code
I: 1) Discuss how high and low-frequency QPOs can be produced by a
highly tilted, geometrically thin accretion disk. 2) Present the first
GRMHD simulation showing the self-consistent formation of a truncated
accretion disk– a proposed disk model for the hard intermediate
accretion state, in which the accretion flow is thick and hot close to
the black hole, while the outer regions of the flow are thin and cool.
3) Describe how QPOs can be generated at the truncation radius (the
radius at which the disk transitions from thick to thin) in a truncated
accretion disk.
External references
- 25030122
- dad36c0c-e004-4754-b2c7-48159eb7c446
