Vortragsdetails

Mittwoch, 30. Januar 2013 - 16:15

Gustavo Dopcke:

"On the IMF of low-metallicity stars"

Zusammenfassung. A fundamental question in the context of structure formation concerns the transition from massive primordial stars to Population I/II stars with typical masses of less than 1 M$A!Q(B, and in particular the physical mechanisms inducing this transition. The purpose of this work is to study the physical mechanisms that shape the stellar IMF at the early stages of the Universe. With this aim, we perform a set of eight hydrodynamic simulations that include sink particles representing contracting protostars. Evidence for fragmentation was found in all cases, and hence we conclude that there is no critical metallicity below which fragmentation is impossible. Nevertheless, there is a clear change in the characteristic mass of the clouds at Z = 10$B!](B4Z_sol. Moreover, we develop a model for the stellar IMF, which accounts for the evolution of simulated clusters. With that, we can recover results from hydrodynamic simulations, and also observations of the Orion Nebulae Cluster. Finally, we find that the resultant stellar mass distribution is highly dependent on the characteristic mass of the cluster, and the mode of mass accretion.