Driven and Decaying Turbulence Simulations of Low-Mass Star Formation: From Clumps to Cores to Protostars

Abstract

Molecular clouds are observed to be turbulent, but the origin of this turbulence is not well understood. As a result, there are two different approaches to simulating molecular clouds, one in which the turbulence is allowed to decay after it is initialized, and one in which it is driven. We use the adaptive mesh refinement (AMR) code, Orion, to perform high-resolution simulations of molecular cloud cores and protostars in environments with both driven and decaying turbulence. We include self-gravity, use a barotropic equation of state, and represent regions exceeding the maximum grid resolution with sink particles. We analyze the properties of bound cores such as size, shape, linewidth, and rotational energy, and we find reasonable agreement with observation. At high resolution, the different rates of core accretion in the two cases have a significant effect on protostellar system development. Clumps forming in a decaying turbulence environment produce high-multiplicity protostellar systems with Toomre-Q unstable disks that exhibit characteristics of the competitive accretion model for star formation. In contrast, cores forming in the context of continuously driven turbulence and virial equilibrium form smaller protostellar systems with fewer low-mass members. Our simulations of driven and decaying turbulence show some statistically significant differences, particularly in the production of brown dwarfs and core rotation, but the uncertainties are large enough that we are not able to conclude whether observations favor one or the other.

arXiv comment16 pages, 17 figures, accepted to ApJ

References in corpus (53)

• Theory of Star Formation
• Control of star formation by supersonic turbulence
• Interstellar Turbulence I: Observations and Processes
• A General Theory of Turbulence-Regulated Star Formation, From Spirals to ULIRGs
• The Stellar IMF from Turbulent Fragmentation
• Dense Cores in Dark Clouds. XIV. N2H+(1-0) maps of dense cloud cores
• The Formation of Brown Dwarfs as Ejected Stellar Embryos
• Star Formation in a Crossing Time
• Dissipation in Compressible MHD Turbulence
• The Energy Dissipation Rate of Supersonic, Magnetohydrodynamic Turbulence in Molecular Clouds
• The Universality of Turbulence in Galactic Molecular Clouds
• The hierarchical formation of a stellar cluster
• High Resolution Submillimeter Constraints on Circumstellar Disk Structure
• Radiation-Hydrodynamic Simulations of Collapse and Fragmentation in Massive Protostellar Cores
• Massive star formation: Nurture, not nature
• The Formation Mechanism of Brown Dwarfs
• Efficiencies of Low-Mass Star and Star Cluster Formation
• A Super-Alfvenic Model of Dark Clouds
• The Burst Mode of Protostellar Accretion
• Massive star formation in 100,000 years from turbulent and pressurized molecular clouds
• The "Mysterious" Origin of Brown Dwarfs
• The Formation of Stellar Clusters: Mass Spectra from Turbulent Molecular Cloud Fragmentation
• Embedding Lagrangian Sink Particles in Eulerian Grids
• The impact of magnetic fields on single and binary star formation
• Accretion in stellar clusters and the IMF
• Outflows and Jets from Collapsing Magnetized Cloud Cores
• Molecular cloud evolution. I. Molecular cloud and thin CNM sheet formation
• Equilibrium Star Cluster Formation
• The Large and Small Scale Structures of Dust in the Star-Forming Perseus Molecular Cloud
• The thermodynamics of collapsing molecular cloud cores using smoothed particle hydrodynamics with radiative transfer
• Two regimes of Turbulent Fragmentation and the stellar IMF from Primordial to Present Day Star Formation
• Brown dwarf formation by gravitational fragmentation of massive, extended protostellar discs
• Protostellar Disks: Formation, Fragmentation, and the Brown Dwarf Desert
• The minimum mass for star formation, and the origin of binary brown dwarfs
• Fragmentation of Molecular Clouds: The Initial Phase of a Stellar Cluster
• The Formation of Self-Gravitating Cores in Turbulent Magnetized Clouds
• The Formation of Stellar Clusters: Gaussian Initial Conditions II
• Gravitational Collapse and Star Formation in Logotropic and Non-Isothermal Spheres
• Limits on the primordial stellar multiplicity
• Numerical requirements for simulations of self gravitating and non-self gravitating disks
• Analysis of Clumps in Molecular Cloud Models: Mass Spectrum, Shapes, Alignment and Rotation
• The Jeans mass and the origin of the knee in the IMF
• Second Core Formation and High Speed Jets: Resistive MHD Nested Grid Simulations
• First MHD Simulation of Collapse and Fragmentation of Magnetized Molecular Cloud Cores
• Bondi-Hoyle Accretion in a Turbulent Medium
• The Formation of Star Clusters I: 3D Simulations of Hydrodynamic Turbulence
• The Mass Spectra of Cores in Turbulent Molecular Clouds and Implications for the Initial Mass Function
• Formation and Collapse of Nonaxisymmetric Protostellar Cores in Planar Magnetic Molecular Clouds
• Protostellar collapse induced by compression. II: rotation and fragmentation
• Protostellar Angular Momentum Evolution during Gravoturbulent Fragmentation
• The Kinematics of Molecular Cloud Cores in the Presence of Driven and Decaying Turbulence: Comparisons with Observations
• A Case Study of Low-Mass Star Formation
• NICMOS/HST Observations of the Embedded Cluster Associated with Mon R2: Constraining the sub-stellar Initial Mass Function

Cited by in corpus (86)

• The Spitzer c2d Legacy Results: Star Formation Rates and Efficiencies; Evolution and Lifetimes
• Comparing the statistics of interstellar turbulence in simulations and observations: Solenoidal versus compressive turbulence forcing
• Stellar, brown dwarf and multiple star properties from a radiation hydrodynamical simulation of star cluster formation
• Probing the evolution of molecular cloud structure: From quiescence to birth
• Stellar, Brown Dwarf, and Multiple Star Properties from Hydrodynamical Simulations of Star Cluster Formation
• On the diversity and statistical properties of protostellar discs
• On the Role of Disks in the Formation of Stellar Systems: A Numerical Parameter Study of Rapid Accretion
• The Importance of Radiative Feedback for the Stellar Initial Mass Function
• The Formation of Low-Mass Binary Star Systems Via Turbulent Fragmentation
• On the Density Distribution in Star-forming Interstellar Clouds
• The Formation and Early Evolution of Low-mass Stars and Brown Dwarfs
• The Fractal Density Structure in Supersonic Isothermal Turbulence: Solenoidal versus Compressive Energy Injection
• Concurrent formation of supermassive stars and globular clusters: implications for early self-enrichment
• Limiting Accretion onto Massive Stars by Fragmentation-Induced Starvation
• Importance of the Initial Conditions for Star Formation - I. Cloud Evolution and Morphology
• Turbulent Driving Scales in Molecular Clouds
• The JCMT Gould Belt Survey: First results from the SCUBA-2 observations of the Ophiuchus molecular cloud and a virial analysis of its prestellar core population
• Mid-Infrared Extinction Mapping of Infrared Dark Clouds: Probing the Initial Conditions for Massive Stars and Star Clusters
• Radiation-Hydrodynamic Simulations of the Formation of Orion-Like Star Clusters I. Implications for the Origin of the Initial Mass Function
• Radiation Feedback, Fragmentation, and the Environmental Dependence of the Initial Mass Function
• Quantifying Observational Projection Effects Using Molecular Cloud Simulations
• The statistical properties of stars and their dependence on metallicity: the effects of opacity
• Dense core formation in supersonic turbulent converging flows
• The dependence of star formation on initial conditions and molecular cloud structure
• The Age, Stellar Content and Star Formation Timescale of the B59 Dense Core
• The Angular Momentum of Magnetized Molecular Cloud Cores: A 2D-3D Comparison
• The Formation and Evolution of Wide-Orbit Stellar Multiples In Magnetized Clouds
• Stellar Kinematics of Young Clusters in Turbulent Hydrodynamic Simulations
• Simulating Star Clusters Across Cosmic Time: I. Initial Mass Function, Star Formation Rates and Efficiencies
• ALMA observations of a high-density core in Taurus: dynamical gas interaction at the possible site of a multiple star formation
• An improved sink particle algorithm for SPH simulations
• Star formation in turbulent molecular clouds with colliding flow
• Stellar mass spectrum within massive collapsing clumps I. Influence of the initial conditions
• The IMF of stellar clusters: effects of accretion and feedback
• Physical Properties of Dense Cores in the Rho Ophiuchi Main Cloud and A Significant Role of External Pressures in Clustered Star Formation
• Protostellar discs formed from turbulent cores
• The Origin of the Stellar Mass Distribution and Multiplicity
• Observation of rotation in star forming regions: clouds, cores, disks, and jets
• The FRIGG project: From intermediate galactic scales to self-gravitating cores
• The influence of the turbulent perturbation scale on prestellar core fragmentation and disk formation
• The ALMA Survey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). VIII. Dynamics of Embedded Dense Cores
• Turbulence, Coherence and Collapse: Three Phases for Core Evolution
• Star Formation in Molecular Clouds
• A likely flyby of binary protostar Z CMa caught in action
• The dynamo effect in decaying helical turbulence
• The Lesser Role of Shear in Star Formation: Insight from the Galactic Ring Survey
• Three-dimensional molecular line transfer: A simulated star-forming region
• The Dynamical State of The Serpens South Filamentary Infrared Dark Cloud
• The Origins of Protostellar Core Angular Momenta
• The relation between accretion rates and the initial mass function in hydrodynamical simulations of star formation
• Stellar mass spectrum within massive collapsing clumps III. Effects of temperature and magnetic field
• Protostellar collapse of magneto-turbulent cloud cores: shape during collapse and outflow formation
• Magnetic field and early evolution of circumstellar disks
• Tracing magnetic field morphology using the Velocity Gradient Technique in the presence of CO self-absorption
• Formation of stellar clusters
• The Properties of Prestellar Discs in Isolated and Multiple Prestellar Systems
• Less wrong: a more realistic initial condition for simulations of turbulent molecular clouds
• Dense cores and star formation in the giant molecular cloud Vela~C
• The highly variable time evolution of star-forming cores identified with dendrograms
• Rotating filament in Orion B: Do cores inherit their angular momentum from their parent filament?
• On the emergent System Mass Function: the contest between accretion and fragmentation
• A submillimetre survey of the kinematics of the Perseus molecular cloud - III. Clump kinematics
• Droplets II: Internal Velocity Structures and Potential Rotational Motions in Pressure-dominated Coherent Structures
• Dense Regions in Supersonic Isothermal Turbulence
• GMC Collisions as Triggers of Star Formation. VI. Collision-Induced Turbulence
• Assessing molecular line diagnostics of triggered star formation using synthetic observations
• The Shapes of Molecular Cloud Cores in Simulations and Observations
• Molecular Line Profiles from Contracting Dense Cores
• Evolution of the Angular Momentum of Molecular Cloud Cores Formed from Filament Fragmentation
• A turbulent origin for the complex envelope kinematics in the young low-mass core Per-Bolo 58
• On estimating angular momenta of infalling protostellar cores from observations
• Alignment of dense molecular core morphology and velocity gradients with ambient magnetic fields
• Turbulence decay and cloud core relaxation in molecular clouds
• The Approach to Collapse of Molecular Clouds
• Assessing the Impact of Astrochemistry on Molecular Cloud Turbulence Statistics
• From Giant H II regions and H II galaxies to globular clusters and compact dwarf ellipticals
• Discovery of Asymmetric Spike-like Structures of the 10 au Disk around the Very Low-luminosity Protostar Embedded in the Taurus Dense Core MC 27/L1521F with ALMA
• An analytical model for the evolution of starless cores I: The constant-mass case
• Shell instability of a collapsing dense core
• Independent Core Rotation in Massive Filaments in Orion
• On the Coagulation and Size Distribution of Pressure Confined Cores
• Externally Fed Accretion onto Protostars
• Turbulence and its connection to episodic accretion in binary YSOs
• Core formation via filament fragmentation and the impact of ambient pressure on it
• Star Cluster Formation in Clouds with Externally Driven Turbulence
• The Milky Way atlas for linear filaments II. clump rotation versus filament orientation