Cooling, gravity and geometry: flow-driven massive core formation

Journal article

We study numerically the formation of molecular clouds in large-scale colliding flows including self-gravity. The models emphasize the competition between the effects of gravity on global and local scales in an isolated cloud. Global gravity builds up large-scale filaments, while local gravity, triggered by a combination of strong thermal and dynamical instabilities, causes cores to form. The dynamical instabilities give rise to a local focusing of the colliding flows, facilitating the rapid formation of massive protostellar cores of a few hundred M_☉. The forming clouds do not reach an equilibrium state, although the motions within the clouds appear to be comparable to virial. The self-similar core mass distributions derived from models with and without self-gravity indicate that the core mass distribution is set very early on during the cloud formation process, predominantly by a combination of thermal and dynamical instabilities rather than by self-gravity.

Authors: Heitsch, F; Hartmann, L; Slyz, A; Devriendt, J; Burkert, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Astronomical Society
• Journal: Astrophysical Journal
• Volume: 674
• Issue: 1
• Pages: 316-328
• Publication date: 2008-02-10
• Acceptance date: 2007-09-15
• DOI: 10.1086/523697
• EISSN: 1538-4357
• ISSN: 0004-637X
• Keywords: SBTMR; instabilities; stars: formation — turbulence; ISM: clouds; methods: numerical; gravitation