Planet and Star Formation - Theory Group

Welcome to the Homepage of the PSF-Theory Group!



A spiral structure imaged in optically scattered light in the protoplanetary disk MWC 758. Density variations of uncertain origin permeate the signal. An ideal target for simulation analysis.<br />(c) Benisty et al. 2015 Zoom Image
A spiral structure imaged in optically scattered light in the protoplanetary disk MWC 758. Density variations of uncertain origin permeate the signal. An ideal target for simulation analysis.
(c) Benisty et al. 2015 [less]
Our group head - P.D. Hubert Klahr.
Our group head - P.D. Hubert Klahr.

We seek to solve riddles in the fields of planet formation, exo-planets, brown dwarfs and massive stars.
Recent years have seen an enormous rise in data about the structures and characteristics of extrasolar planetary systems grace to missions like Kepler, Corot and surveys performed by earth bound instrument like SUPERWasp, ELODIE, HARPS etc.

The naive picture of our sun being very normal and our solar system being quite unusual compared to the galactic population, that existed in the early years of (exo)planetary exploration has hence been severely challenged.

To achieve the goal of a theoretical and hence, thorough understanding of those objects, we perform work on paper for the simpler parts as well as heavy numerical supercomputing for tough nonlinear problems.

Collaborations with other groups that take similar interests as we do, are important for bringing our work into the bigger picture of astrophysics. Especially to mention here are ITA (C. Dullemond, Dust models), and other Institutes (R. Kuiper, Star formation) etc.







As appetizer for your curiosity we have assembled a small overview of our current work:

Streaming instabilities are a result of sufficient dust densities and large relative flow velocities between dust and gas. This instability itself produces the turbulence that makes it possible to clump dust sufficiently together in order to become self-gravitating and thus overcome the meter-barrier in planet formation. This mechanism is thus of significant interest for the scientific community.

DFG 1385 - Gravoturbulent planetesimal formation in the early solar system

Streaming instabilities are a result of sufficient dust densities and large relative flow velocities between dust and gas. This instability itself produces the turbulence that makes it possible to clump dust sufficiently together in order to become self-gravitating and thus overcome the meter-barrier in planet formation. This mechanism is thus of significant interest for the scientific community. [more]
Over a period of 6 years, DFG is funding research projects within its SPP framework (DFG-Schwerpunktprogramm) "Building a Habitable Earth". The SPP will contribute to the still open question how Earth became the only known habitable planet.

DFG 1833 - Building a habitable earth

Over a period of 6 years, DFG is funding research projects within its SPP framework (DFG-Schwerpunktprogramm) "Building a Habitable Earth". The SPP will contribute to the still open question how Earth became the only known habitable planet. [more]
Hydrodynamic instabilities may lead to vortex formation and thus initiate dust concentration in the inner Protoplanetary disk (&lt;100Au) or lead to direct gravitational collapse and giant planet collapse in the outer disk.<br />We investigate various scenarios for the stability and involved timescales of those features in shearing boxes, global 2D and 3D simulations.

Hydrodynamic instabilities and gravoturbulent disk fractionation

Hydrodynamic instabilities may lead to vortex formation and thus initiate dust concentration in the inner Protoplanetary disk (<100Au) or lead to direct gravitational collapse and giant planet collapse in the outer disk.
We investigate various scenarios for the stability and involved timescales of those features in shearing boxes, global 2D and 3D simulations. [more]
The amplification or dampening of hydrodynamically instable features may be modified by the presence of dust. Also the dynamics of dust will surely follow pressure maxima in a protoplanetary disc.<br />Therefore there is ample potential for complex interactions between the gas and dust material which we aim to study.

Hydro-Dust-Interactions

The amplification or dampening of hydrodynamically instable features may be modified by the presence of dust. Also the dynamics of dust will surely follow pressure maxima in a protoplanetary disc.
Therefore there is ample potential for complex interactions between the gas and dust material which we aim to study. [more]
A sufficiently massive planet will induce spiral arms, gap formation, migration and accretion shocks in his surrounding disk. We attempt to understand how all those processes backreact onto planetary formation and disk evolution.

Planet-Disk-Interactions

A sufficiently massive planet will induce spiral arms, gap formation, migration and accretion shocks in his surrounding disk. We attempt to understand how all those processes backreact onto planetary formation and disk evolution. [more]
In order to link planetary population synthesis modells with observations, evolution calculations for single planets are needed. This is obvious as no planet is observed at an age of zero. We use atmospheric and structure modells planets, as well as atmospheric loss and bloating mechanisms for giant and rocky planets to develop our understanding of planetary populations.

Planets and their evolution

In order to link planetary population synthesis modells with observations, evolution calculations for single planets are needed. This is obvious as no planet is observed at an age of zero. We use atmospheric and structure modells planets, as well as atmospheric loss and bloating mechanisms for giant and rocky planets to develop our understanding of planetary populations. [more]
 
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