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EPoS |
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EPoS Contribution
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Gravoturbulent Star Formation
Ralf Klessen Zentrum für Astronomie der Universität Heidelberg, Heidelberg, Germany | |
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Stars form by gravoturbulent fragmentation of interstellar gas clouds.
The supersonic turbulence ubiquitously observed in Galactic molecular
gas generates strong density fluctuations with gravity taking over in
the densest and most massive regions. Collapse sets in to build up
stars and star clusters.
Turbulence plays a dual role. Or global scales it provides support, while at the same time it can promote local collapse. Stellar birth is thus intimately linked to the dynamical behavior of parental gas cloud, which governs when and where protostellar cores form, and how they contract and grow in mass via accretion from the surrounding cloud material to build up stars. Slow, inefficient, isolated star formation is a hallmark of turbulent support, whereas fast, efficient, clustered star formation occurs in its absence. The stellar mass spectrum is determined by the complex interplay between turbulent molecular cloud structure (as initial condition for gravitational collapse), the subsequent protostellar accretion (which again is influenced by the turbulent cloud environement) and possible stellar-dynamical effects in the nascent embedded star cluster (like ejection from multiple systems during the main accretion phase). I will discuss recent advances in dynamical star formation theory and discuss results from numerical calculations of gravoturbulent cloud fragmentation and early evolution of embedded nascent star clusters. | |