Johannes Bahrenberg

PhD student in computational astrophysics
MPIA, Heidelberg, Germany

The inner boundary

The disk is circling around a Herbig Ae star with 2.5 solar masses, which dominates the heating in the disk. The inner boundary lies close to the star, at 0.1 au.

Photo-evaporative wind

Thermally induced, largely laminar outflow with 4-6 km /s speed above the disk surface. More in Research.

The dead zone inner edge (DZIE)

Connects regions with well (active) and poor (dead) coupling of material and magnetic field. At the DZIE pressure maxima occur and pebbles are trapped, eventually forming a planet. Therefore, its exact location is crucial.

I tackle this in my simulations by combining an analytical temperature prescription with detailed magnetic resistivity tables.

Gap formation

The surface density is reduced due to a high concentration of magnetic flux (see left side). This indicates that gaps can form purely through magnetic effects, without planets carving them.

Magnetic wind

Fast outflows with high turbulence, efficiently removing disk material and angular momentum from the disk. This wind structure is mirroring the magnetic field structure on the left.

Strong magnetic field bands

Large magnetic flux (strong, dense field lines) is carrying material efficiently away from the disk surface, potentially carving gaps.

Wide polar domain

The domain comes within 0.001 rad of the poles, thus allowing conclusions to be drawn about movements high up in the atmosphere, e.g. potential jets.

Magneto-hydrodynamics simulation of a protoplanetary disk showing winds and magnetic flux concentration. Left: Poloidal magnetic field. Right: Density and poloidal velocity streams. For more details, see Bahrenberg et al. (in prep.).

About me

Hi, I’m a second-year PhD student at Max Planck Institute for Astronomy (MPIA), working with Mario Flock and the RAPTOR group. I study the effect of magnetic fields on protoplanetary disk evolution and planet formation via numerical magneto-hydrodynamics simulations.

In order to study how magnetic fields affect protoplanetary disks, I perform high performance simulations with the PLUTO code. Right now I’m focused on distinct features of magnetic and photo-evaporative winds, which both launch material from the disk surface. With a background in radiative transfer simulations, I aim to connect the physical processes in protoplanetary disks to observable signatures (see Research).

Before my PhD I studied Physics at Heidelberg University and worked at German Aerospace Center (DLR) in Berlin. Outside of research I enjoy exploring the outdoors on my bicycle.

About me

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