2001/10/19 by V. Ossenkopf, Volker Ossenkopf, Ralf S. Klessen +2 · 3 citations
Physics and Astronomy · #Astrophysics #Astrophysics and Star Formation Studies #Atomic and Molecular Physics #Density contrast #Extinction (optical mineralogy) #Gravitational collapse #Mechanics #Molecular cloud #Physics #Serpens #Star formation #Stars #Stellar, planetary, and galactic studies #Turbulence #astro-ph
paper · pdf · doi:10.1051/0004-6361:20011324
published as Astron.Astrophys. 379 (2001) 1005-1016 · 12 pages, 9 figures, A&A in press
arxiv created 2001/10/19 · openalex publication_date 2001/12/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
To study the interaction of star-formation and turbulent molecular cloud structuring, we analyse numerical models and observations of self-gravitating clouds using the Δ-variance as statistical measure for structural characteristics. In the models we resolve the transition from purely hydrodynamic turbulence to gravitational collapse associated with the formation and mass growth of protostellar cores. We compare models of driven and freely decaying turbulence with and without magnetic fields. Self-gravitating supersonic turbulence always produces a density structure that contains most power on the smallest scales provided by collapsed cores as soon as local collapse sets in. This is in contrast to non-self-gravitating hydrodynamic turbulence where the Δ-variance is dominated by large scale structures. To detect this effect in star-forming regions observations have to resolve the high density contrast of protostellar cores with respect to their ambient molecular cloud. Using the 3 mm continuum map of a star-forming cluster in Serpens we show that the dust emission traces the full density evolution. On the contrary, the density range accessible by molecular line observations is insufficient for this analysis. Only dust emission and dust extinction observations are able to to determine the structural parameters of star-forming clouds following the density evolution during the gravitational collapse.