Oral Presentation

Simulating the M87 engine with the Black Hole Accretion Code (BHAC)

Author(s): Oliver Porth (ITP Frankfurt, Germany)

Presenter: Oliver Porth (Institute for Theoretical Physics, Frankfurt am Main, D-60438, Germany)

I will present simulations with the newly developed code "BHAC", a massively parallel 2D and 3D adaptive mesh refinement GRMHD code.
Recent observational breakthroughs render M87 a prime target to test our theoretical and numerical models of cosmic jets: The presence of gradual flow acceleration on scales up to 10^5 rg, the transition from a parabolic flow geometry to a conical one at a location corresponding roughly to the Bondi radius and the HST-1 feature now ask for a detailed MHD-modeling.
I will discuss the impact of the jet environment (disk-wind respectively ISM) on the causality and stability with respect to internal and external MHD instabilities.
We find that over-dense flows can experience a special kind of Rayleigh-Taylor instability due to jet reconfinement. This mechanism could be responsible for the transition from parabolic to conical flow observed in M87.
These considerations will be put to the test with large-scale adaptive-mesh-refinement GRMHD simulations taylored to M87.