Star formation in turbulent interstellar gas clouds
Dr. Ralf Klessen (Astrophysikalisches Institut Potsdam)
Donnerstag, den 22.5.2003 um 10 Uhr c.t., PN-201
Abstract:
Understanding the star formation process is central to much of modern astrophysics. For several decades it has been thought that stellar birth is primarily controlled by the interplay between gravity and magnetostatic support, modulated by ambipolar diffusion. Recently, however, both observational and numerical work has begun to suggest that supersonic interstellar turbulence rather than magnetic fields controls star formation. Supersonic turbulence can provide support against gravitational collapse on global scales, while at the same time it produces localized density enhancements that allow for collapse on small scales. The efficiency and timescale of stellar birth in Galactic molecular clouds strongly depend on the properties of the interstellar turbulent velocity field, with slow, inefficient, isolated star formation being a hallmark of turbulent support, and fast, efficient, clustered star formation occurring in its absence.
I will review the current progress in the field of theoretical star formation and identify some of the open issues that still need to be resolved to achieve a comprehensive understanding of the stellar birth.