Dynamic Cores in Hydrostatic Disguise

@article{BallesterosParedes2003DynamicCI,
  title={Dynamic Cores in Hydrostatic Disguise},
  author={Javier Ballesteros-Paredes and Ralf S. Klessen and Enrique V{\'a}zquez-Semadeni},
  journal={The Astrophysical Journal},
  year={2003},
  volume={592},
  pages={188-202}
}
We discuss the column density profiles of "cores" in three-dimensional smoothed particle hydrodynamics (SPH) numerical simulations of turbulent molecular clouds. The SPH scheme allows us to perform a high spatial resolution analysis of the density maxima (cores) at scales between ~0.003 and 0.3 pc. We analyze simulations in three different physical conditions: large-scale driving (LSD), small-scale driving (SSD), and random Gaussian initial conditions without driving (GC), each one at two… Expand
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References

SHOWING 1-10 OF 53 REFERENCES
The Formation of Stellar Clusters: Gaussian Cloud Conditions. II.
Using hydrodynamic simulations, we investigate the time evolution and fragmentation of regions within molecular clouds that have lost their turbulent support, leading to gravitational contraction.Expand
Physical versus Observational Properties of Clouds in Turbulent Molecular Cloud Models
We examine the question of how well the physical properties of clumps in turbulent molecular clouds can be determined by measurements of observed clump structures. To do this, we compare simulatedExpand
Modelling accretion in protobinary systems
A method for following fragmentation simulations further in time using smoothed particle hydrodynamics (SPH) is presented. In a normal SPH simulation of the collapse and fragmentation of a molecularExpand
Kinetic and Structural Evolution of Self-gravitating, Magnetized Clouds: 2.5-Dimensional Simulations of Decaying Turbulence
The molecular component of the Galaxy is comprised of turbulent, magnetized clouds, many of which are self-gravitating and form stars. To develop an understanding of how these clouds' kinetic andExpand
CLOUDS AS TURBULENT DENSITY FLUCTUATIONS: IMPLICATIONS FOR PRESSURE CONFINEMENT AND SPECTRAL LINE DATA INTERPRETATION
We examine the idea that diffuse H I and giant molecular clouds and their substructure form as density fluctuations induced by large-scale interstellar turbulence. We do this by closely investigatingExpand
Turbulent Flow-driven Molecular Cloud Formation: A Solution to the Post-T Tauri Problem?
We suggest that molecular clouds can be formed on short timescales by compressions from large scale streams in the interstellar medium (ISM). In particular, we argue that in the Taurus-AurigaExpand
Gravitational collapse in turbulent molecular clouds. I. gasdynamical turbulence
Observed molecular clouds often appear to have very low star formation efficiencies and lifetimes an order of magnitude longer than their free-fall times. Their support is attributed to the randomExpand
The Formation of Stellar Clusters: Gaussian Cloud Conditions. I.
The isothermal dynamical evolution of a clumpy molecular cloud region and its fragmentation into a protostellar cluster is investigated numerically. The initial density distributions are generatedExpand
A Holistic Scenario of Turbulent Molecular Cloud Evolution and Control of the Star Formation Efficiency: First Tests
We compile a holistic scenario for molecular cloud (MC) evolution and control of the star formation efficiency (SFE) and present a first set of numerical tests of it. A lossy compressible cascade canExpand
Protostellar Collapse in a Rotating, Self-gravitating Sheet
We extend our previous calculations of the self-gravitational collapse of an initially sheetlike, nonrotating cloud to include rotation at a wide range of initial rates (10-15 to 10-13 rad s-1). TheExpand
...
1
2
3
4
5
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