Montag, 4. Juli 2011 - 11:30
"Importance of the Initial Conditions for Star Formation"
Zusammenfassung. Theoretical star formation studies are dominated by large-scale simulations with many different initial conditions and a large variety of physical processes. The comparison of the obtained results strongly focuses on the different processes like radiation, magnetic fields and chemistry. In contrast the initial conditions are mostly not considered to be of primary interest. In order to determine their importance, we performed simulations of collapsing cloud cores with the same mass, volume and energy content but different initial density profiles and different turbulent velocity fields. Our results show a strong influence of these initial conditions on the initial mass function of the protostars, the formation scenario of protostellar clusters and their substructure. Strongly concentrated density profiles support the formation of massive protostars and dense clusters with little substructure, while initially flat density distributions are more likely to form clusters with many low-mass protostars and a larger degree of subclustering. Overall we conclude that the choice of the initial conditions may easily predetermine the obtained properties of a collapsing core. A comparison of simulations with different or not precisely defined initial conditions easily results in misleading conclusions.