Saturation level of turbulence in collapsing gas clouds

Abstract

We investigate the physical mechanism that decides the saturation level of turbulence in collapsing gas clouds. We perform a suite of high-resolution numerical simulations following the collapse of turbulent gas clouds with various effective polytropic exponents ${\gamma }_{\mathrm{eff}}$, initial Mach numbers ${\mathcal{M}}_0$, and initial turbulent seeds. Equating the energy injection rate by gravitational contraction and the dissipation rate of turbulence, we obtain an analytic expression of the saturation level of turbulence, and compare it with the numerical results. Consequently, the numerical results are well described by the analytic model, given that the turbulent driving scale in collapsing gas clouds is one-third of Jeans length of collapsing core. These results indicate that the strength of turbulence at the first core formation in the early universe/present-day star-formation process can be estimated solely by ${\gamma }_{\mathrm{eff}}$.

arXiv comment12 pages, 8 figures, 2 tables, accepted for publication in ApJ

References in corpus (53)

• Theory of Star Formation
• A Multi-Code Analysis Toolkit for Astrophysical Simulation Data
• The Formation of the First Stars. I. The Primordial Star Forming Cloud
• The Stellar IMF from Turbulent Fragmentation
• How small were the first cosmological objects?
• Enzo: An Adaptive Mesh Refinement Code for Astrophysics
• Simulations of Early Structure Formation: Primordial Gas Clouds
• The Energy Dissipation Rate of Supersonic, Magnetohydrodynamic Turbulence in Molecular Clouds
• Formation of Primordial Stars in a LCDM Universe
• Simulations on a Moving Mesh: The Clustered Formation of Population III Protostars
• The Formation of a Bound Star Cluster: From the Orion Nebula Cluster to the Pleiades
• The Formation and Fragmentation of Disks around Primordial Protostars
• Protostar Formation in the Early Universe
• Cosmological Formation of Low-Mass Objects
• Grackle: a Chemistry and Cooling Library for Astrophysics
• The initial mass function : from Salpeter 1955 to 2005
• The Mass Spectrum of the First Stars
• A new Jeans resolution criterion for (M)HD simulations of self-gravitating gas: Application to magnetic field amplification by gravity-driven turbulence
• Formation of Primordial Protostars
• Gravitational fragmentation in turbulent primordial gas and the initial mass function of Population III stars
• Building up the Population III initial mass function from cosmological initial conditions
• Radiation Magnetohydrodynamic Simulations of Protostellar Collapse: Protostellar Core Formation
• The generation of strong magnetic fields during the formation of the first stars
• Suppression of H_2 Cooling in the Ultraviolet Background
• Magnetic Fields in Population III Star Formation
• The Birth of a Massive First-Star Binary
• Adiabatic Heating of Contracting Turbulent Fluids
• Simulation of primordial object formation
• Formation and survival of Population III stellar systems
• The Formation of Population III Stars in Gas Accretion Stage: Effects of Magnetic Fields
• The mass of first stars
• Star Formation in Self-Gravitating Turbulent Fluids
• Formation sites of Population III star formation: The effects of different levels of rotation and turbulence on the fragmentation behavior of primordial gas
• Merge or survive: Number of Population III stars per minihalo
• The importance of magnetic fields for the initial mass function of the first stars
• Magnetic field amplification during gravitational collapse - Influence of initial conditions on dynamo evolution and saturation
• Seeding the Second Star: enrichment from population III, dust evolution, and cloud collapse
• Does Turbulent Pressure Behave as a Logatrope?
• Formation and Disruption of Cosmological Low Mass Objects
• Magnetic field amplification in accretion discs around the first stars: implications for the primordial IMF
• Fragmentation induced starvation in Population III star formation: a resolution study
• ALMA observations of a misaligned binary protoplanetary disk system in Orion
• Formation of Wide Binaries by Turbulent Fragmentation
• Warm CO gas generated by possible turbulent shocks in a low-mass star-forming dense core in Taurus
• Strongly misaligned triple system in SR 24 revealed by ALMA
• The formation of protostellar binaries in primordial minihalos
• Pop. III stars from turbulent fragmentation at redshift ~ 11
• Molecular cloud formation by compression of magnetized turbulent gas subjected to radiative cooling
• Magnetohydrodynamic effect on first star formation: prestellar core collapse and protostar formation
• Non-adiabatic turbulence driving during gravitational collapse
• Amplification of turbulence in contracting prestellar cores in primordial minihalos
• Compression of turbulent magnetized gas in Giant Molecular Clouds
• Spiral arm instability -- III. Fragmentation of primordial protostellar discs

Cited by in corpus (4)

• Formation of Massive and Wide First-star Binaries in Radiation Hydrodynamics Simulations
• Non-ideal magnetohydrodynamic simulations of the first star formation: the effect of ambipolar diffusion
• Amplification and saturation of turbulent magnetic field in collapsing primordial gas clouds
• Impeding Turbulence Decay in Self-gravitating Cloud Cores