Masters Project Proposals

A number of masters projects and colloquia subjects are possible, in connection with on-going  projects in the Numerical Astrophysics group. For more detailed information, contact one of us for a discussion .

Here are the main areas, and the corresponding questions that the projects could address:

Astrophysical Jets

Hydrodynamics and magnetohydrodynamics of jets from newborne stars, and / or from AGNs. Current questions include: What determines the distribution of the background magnetic field in the accretion disc, and what is the consquence for the collimation of the jet?   What is the role of magnetic instabilities - are global ones such as kinks destructive?  Are local ones that lead to dissipation stabilizing?  What determines the "mass loading" of the jet?

Contacts: Åke Nordlund, Rachid Ouyed

Gamma Ray Bursts

Hydrodynamics and magnetohydrodynamics near black holes: e.g., construction and visualization of self-consistent numerical solutions of "collapsars" / "hypernovae" - rapidly accreting black holes resulting from the collapse of high mass stars. This is a very "hot" research topic, where we have a chance to advance right up to the forefront of GRB research.

Contacts: Åke Nordlund, Axel Brandenburg, Rachid Ouyed

Supersonic MHD Turbulence and Star Formation

Numerical MHD simulations of  conditions similar to those in cold molecular clouds.  Current questions: What controls the distribution of the mass of newborn stars (the Initial Mass Function)? How does it scale with physical conditions?  What was it like in the early Universe? In star burst galaxies? Again a very hot topic, where we already are at the forefront :-!

Contacts: Åke Nordlund, Paolo Padoan

Galaxy Formation and Cluster Cooling Flows

Coupled magnetohydrodynamic and particle simulations of galaxy clusters and cooling flows in galactic halos. Current questions: What are the fundamental properties of cooling flows?  How intermittent are they? What is required to get the "right" angular momentum of newborne galaxies, and what are the implications for cosmological models? What is the importancy or not of intermittency / clumping in the galactic cooling flows?

Contact: Åke Nordlund

Galactic Turbulence and Supernovae

Interstellar turbulence is mot likely ultimately driven by supernovae explosions. Can direct comparisons with observatoinal diagnostics be made? How does the "cascade" of energy work, down to cold molecular clouds, where stars are borne.  What is the role of galactic "chimneys" and "worms"?  What are the high velocity clouds - fall-back or primordial cooling flow?

Contacts: Åke Nordlund,   Axel Brandenburg

Accretion Discs

Investigations of self sustained, magnetically driven turbulence in accretion disks.  There are many questions, e.g.  about the nature of the dynamo action, the dissipation, and radiative energy transfer and diagnostics.  Here is an area where the near future will see direct comparisons between "synthetic observations" (diagnostics from numerical models) and real observations.

Contacts: Axel Brandenburg, Åke Nordlund, Ulf Torkelsson

Magnetic Dissipation and Coronal Heating

How is externally imposed work dissipated in an MHD plasma? For example; how are accretion disc coronae heated, and how is the solar corona heated?

Contacts: Åke Nordlund, Klaus Galsgaard

Astrophysical Dynamos

Fundamental questions about the spontaneous creation of magnetic fields in astrophysical plasmas.  What are the topological mechanisms responsible for dynamo action?

Contacts: Åke Nordlund, Axel Brandenburg

Stellar Convection and Oscillations

The structure of convection in stars, and its interaction with stellar oscillations.   What is the nature of the driving and damping of stellar oscillations?

Contacts: Åke Nordlund, Bob Stein, Jørgen Christensen-Dalsgaard

Turbulence

Fundamental questions about the nature of turbulence and magneto-turbulence.

Contacts: Åke Nordlund