» Back to overview
Proposing Institution

Physikalisches Institut, Universität zu Köln
Project Manager

Dr. Daniel Seifried
Zülpicher Str. 77
50937 Köln
In this proposed project we plan to study the collapse of high-mass, rotating and magnetised molecular cloud cores. The combination of rotation and magnetic fields leads to the occurrence of outflow phenomena. Such outflows already exist in the early phase of stellar evolution and can be produced self-consistently in our numerical simulations. We especially focus in this project on the stability properties of the disk surrounding the protostar formed during the collapse. We plan to examine in detail how the outflow launched by magnetic forces influences the fragmentation properties of the disk during its long term evolution, i.d. whether it enhances or suppresses the fragmentation of the disk into several, distinct protostars. Also the theoretically predicted correlation between accretion rates of the disk and the outflow rates will be studied in the proposed project. Here it is of interest to examine in detail the close interaction of the outflows and the accretion onto the protostar. A crucial point is the question whether an outflow produced by magnetic fields can be powerful enough to significantly reduce or even completely terminate the accretion onto the protostar. In every case the outflow will influence the accretion history of the protostar and hence possibly also the final mass the star ends up with.As we focus on the long term evolution of the disk we make use of the sink particle algorithm. With this technique we are able to follow the evolution of the accretion disk over a longer range of time. We also intend to examine the influence of the initial conditions on the fragmentation and accretion properties of the disk. Therefor we plan to perform several simulations changing the initial cloud core mass, the initial rotation velocity and the initial magnetic field strength. The resulting number of simulations to be performed and the large amount of computing power for every individual simulation make the use of a super computer like HLRB-II necessary.

Impressum, Conny Wendler