Fragmentation in a centrally condensed protostar⋆

Centrally condensed turbulent cores: Massive stars or fragmentation?

We present numerical investigations into the formation of massive stars from turbulent cores of density gradient ρ ∝ r. The results of five hydrodynamical simulations are described, following the collapse of the core, fragmentation and the formation of small clusters of protostars. We generate two different initial turbulent velocity fields corresponding to power-law spectra P ∝ k and P ∝ k, an...

Accretion onto a primordial protostar

We present a three-dimensional numerical simulation that resolves the formation process of a Population III star down to a scale of ∼ 100 AU. The simulation is initialized on the scale of a dark matter halo of mass ∼ 106M that virializes at z ∼ 20. It then follows the formation of a fully-molecular central core, and traces the accretion from the diffuse dust-free cloud onto the protostellar cor...

Turmoil in Orion: The Nearest Massive Protostar

I discuss different theories of massive star formation: formation from massive cores, competitive Bondi-Hoyle accretion, and protostellar collisions. I summarize basic features of the Turbulent Core Model (TCM). I then introduce the Orion Kleinmann-Low (KL) region, embedded in the Orion Nebula Cluster (ONC) and one of the nearest regions of massive star formation. The KL region contains three p...

Protostar formation in the early universe.

The nature of the first generation of stars in the universe remains largely unknown. Observations imply the existence of massive primordial stars early in the history of the universe, and the standard theory for the growth of cosmic structure predicts that structures grow hierarchically through gravitational instability. We have developed an ab initio computer simulation of the formation of pri...

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