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(Abridged) We explore, by means of a large ensemble of SPH simulations, how the level of turbulence affects the collapse and fragmentation of a star-forming core. All our simulated cores have the same, except that we vary (a) the initial…

Astrophysics · Physics 2014-10-13 Simon P. Goodwin , Anthony P Whitworth , Derek Ward-Thompson

Recent numerical studies suggest that magnetic fields play an important role in primordial star formation in the early universe. However, the detailed evolution of the magnetic field in the collapse phase still has uncertainties because of…

Astrophysics of Galaxies · Physics 2024-02-27 Sho Higashi , Hajime Susa , Christoph Federrath , Gen Chiaki

The formation of astrophysical structures, such as stars, compact objects but also galaxies, entail an,enhancement of densities by many orders of magnitude which occurs through gravitational collapse. The role played by turbulence during…

Astrophysics of Galaxies · Physics 2021-11-03 Patrick Hennebelle

The turbulent motion within molecular clouds is a key factor controlling star formation. Turbulence supports molecular cloud cores from evolving to gravitational collapse and hence sets a lower bound on the size of molecular cloud cores in…

Solar and Stellar Astrophysics · Physics 2015-06-23 Yang Gao , Haitao Xu , Chung K. Law

The observed rapid onset of star formation in molecular clouds requires rapid formation of dense fragments which can collapse individually before being overtaken by global gravitationally-driven flows. Many previous investigations have…

Astrophysics · Physics 2009-11-13 F. Heitsch , L. Hartmann , A. Burkert , ;

We summarize recent numerical results on the control of the star formation efficiency (SFE), addressing the effects of turbulence and the magnetic field strength. In closed-box numerical simulations, the effect of the turbulent Mach number…

Astrophysics · Physics 2009-11-11 Enrique Vazquez-Semadeni

The primordial clouds in the mini-halos hatch the first generation stars of the universe, which play a crucial role in cosmic evolution. In this paper, we investigate how the turbulence impacts the structure of primordial star-forming…

Astrophysics of Galaxies · Physics 2024-03-14 Ching-Yao Tang , Ke-Jung Chen

We study the turbulence induced in the dust layer of a protoplanetary disk based on the energetics of dust accretion due to gas drag. We estimate turbulence strength from the energy supplied by dust accretion, using the radial drift…

Earth and Planetary Astrophysics · Physics 2015-05-30 Taku Takeuchi , Takayuki Muto , Satoshi Okuzumi , Naoki Ishitsu , Shigeru Ida

We investigate the properties of highly compressible turbulence, the compressibility arising from a small effective polytropic exponent $\gamma_e$ due to cooling. In the limit of small $\gamma_e$, the density jump at shocks is shown to be…

Astrophysics · Physics 2009-10-28 E. Vazquez-Semadeni , T. Passot , A. Pouquet

We examine the physical parameters that affect the accumulation of gas in molecular clouds to high column densities where the formation of stars takes place. In particular, we analyze the dense gas mass fraction (DGMF) in a set of…

Astrophysics of Galaxies · Physics 2015-06-15 Jouni Kainulainen , Christoph Federrath , Thomas Henning

We review the main results from recent numerical simulations of turbulent fragmentation and star formation. Specifically, we discuss the observed scaling relationships, the ``quiescent'' (subsonic) nature of many star-forming cores, their…

Astrophysics · Physics 2008-11-26 Javier Ballesteros-Paredes

We summarize the current status of the turbulent model of star formation in turbulent molecular clouds. In this model, clouds, clumps and cores form a hierarchy of nested density fluctuations caused by the turbulence, and either collapse or…

Astrophysics · Physics 2007-05-23 Enrique Vazquez-Semadeni

It is understood in a general sense that turbulent fluid motion below the shock front in a core-collapse supernova stiffens the effective equation of state of the fluid and aids in the revival of the explosion. However, when one wishes to…

High Energy Astrophysical Phenomena · Physics 2025-11-24 David Calvert , Michael Redle , Bibek Gautam , Charles J. Stapleford , Carla Fröhlich , James P. Kneller , Matthias Liebendorfer

We performed numerical simulations of supersonic isothermal turbulence driven by mostly compressive large-scale forcing, using both a static grid and adaptive mesh refinement with an effective resolution N=768^3. After a transient phase…

We investigate the amplification of turbulence through gravitational contraction of the primordial gas in minihalos. We perform numerical simulations to follow the cloud collapse, assuming polytropic equations of state for different initial…

Astrophysics of Galaxies · Physics 2021-07-21 Sho Higashi , Hajime Susa , Gen Chiaki

We performed simulations of self-gravitating hydrodynamic turbulence to model the formation of filaments, clumps and cores in molecular clouds. We find that when the mass on the initial computational grid is comparable to the Jeans mass,…

Astrophysics · Physics 2007-05-23 David A. Tilley , Ralph E. Pudritz , James Wadsley

The kinetic energy of supersonic turbulence within interstellar clouds is subject to cooling by dissipation in shocks and subsequent line radiation. The clouds are therefore susceptible to a condensation process controlled by the specific…

Astrophysics of Galaxies · Physics 2020-02-05 Eric Keto , George B. Field , Eric G. Blackman

Turbulence plays a key role in star formation in molecular clouds, affecting star cluster primordial properties. As modelling present-day objects hinges on our understanding of their initial conditions, better constraints on turbulence can…

Astrophysics of Galaxies · Physics 2020-10-14 Piero Trevisan , Mario Pasquato , Alessandro Ballone , Michela Mapelli

Abundant observational evidence indicates that the cooling time t_cool of the hot ambient medium pervading a massive galaxy does not drop much below 10 times the freefall time t_ff at any radius. Theoretical models have accounted for this…

Astrophysics of Galaxies · Physics 2018-12-05 G. M. Voit

We investigate the process of cloud cavitation collapse through large-scale simulation of a cloud composed of 12500 gas bubbles. A finite volume scheme is used on a structured Cartesian grid to solve the Euler equations, and the bubbles are…

Computational Physics · Physics 2019-06-12 Ursula Rasthofer , Fabian Wermelinger , Petr Karnakov , Jonas Šukys , Petros Koumoutsakos
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