Star formation in unbound giant molecular clouds: the origin of OB associations?
arXiv:astro-ph/0503141 · doi:10.1111/j.1365-2966.2005.08942.x
Abstract
We investigate the formation of star clusters in an unbound GMC, where the supporting kinetic energy is twice as large as the cloud's self-gravity. This cloud manages to form a series of star clusters and disperse, all within roughly 2 crossing times (10 Myr), supporting recent claims that star formation is a rapid process. Simple assumptions about the nature of the star formation occurring in the clusters allows us to place an estimate for the star formation efficiency at about 5 to 10 %, consistent with observations. We also propose that unbound clouds can act as a mechanism for forming OB associations. The clusters that form in the cloud behave as OB subgroups. These clusters are naturally expanding from one another due to unbound nature of the flows that create them. The properties of the cloud we present here are are consistent with those of classic OB associations.
11 pages, 5 figures, Accepted for publication in MNRAS. The authors would like to dedicate this paper to Adriaan Blaauw, on the occasion of his 90th birthday
References in corpus (2)
Cited by in corpus (89)
- Theory of Star Formation
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- Unbound Young Stellar Systems: Star Formation on the loose
- Ionization--induced star formation V: Triggering in partially unbound clusters
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- The Formation of Star Clusters II: 3D Simulations of Magnetohydrodynamic Turbulence in Molecular Clouds
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- Simulating radiative feedback and star cluster formation in GMCs: I. Dependence on gravitational boundedness
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- The young stellar population of NGC 4214 as observed with HST. II. Results
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- The Clustering Behavior of Pre-Main Sequence Stars in NGC 346 in the Small Magellanic Cloud
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- Effect of Different Stellar Galactic Environments on Planetary Discs I: The Solar Neighbourhood and the Birth Cloud of the Sun
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- A Young GMC Formed at the Interface of Two Colliding Supershells: Observations Meet Simulations
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- Stellar and substellar initial mass function: a model that implements gravoturbulent fragmentation and accretion
- Multi-wavelength Study of Young Massive Star Clusters in the Interacting Galaxy ARP 24
- SIRIUS project II: a new tree-direct hybrid code for smoothed particle hydrodynamics/N-body simulations of star clusters
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