How first hydrostatic cores, tidal forces and gravo-turbulent fluctuations set the characteristic mass of stars

Abstract

The stellar initial mass function (IMF) is playing a critical role in the history of our universe. We propose a theory that is based solely on local processes, namely the dust opacity limit, the tidal forces and the properties of the collapsing gas envelope. The idea is that the final mass of the central object is determined by the location of the nearest fragments, which accrete the gas located further away, preventing it to fall onto the central object. To estimate the relevant statistics in the neighbourhood of an accreting protostar, we perform high resolution numerical simulations. We also use these simulations to further test the idea that fragmentation in the vicinity of an existing protostar is determinant in setting the peak of the stellar mass spectrum. We develop an analytical model, which is based on a statistical counting of the turbulent density fluctuations, generated during the collapse, that are at least equal to the mass of the first hydrostatic core, and sufficiently important to supersede tidal and pressure forces to be self-gravitating. The analytical mass function presents a peak located at roughly 10 times the mass of the first hydrostatic core in good agreement with the numerical simulations. Since the physical processes involved are all local, i.e. occurs at scales of a few 100 AU or below, and do not depend on the gas distribution at large scale and global properties such as the mean Jeans mass, the mass spectrum is expected to be relatively universal.

arXiv commentaccepted for publication in ApJ

References in corpus (43)

• Galactic Stellar and Substellar Initial Mass Function
• On the variation of the Initial Mass Function
• Cosmological Hydrodynamics with Adaptive Mesh Refinement: a new high resolution code called RAMSES
• A Universal Stellar Initial Mass Function? A Critical Look at Variations
• Competitive accretion in embedded stellar cluster
• Analytical theory for the initial mass function: CO clumps and prestellar cores
• Rosseland and Planck Mean Opacities for Protoplanetary Discs
• The Universality of the Stellar IMF
• The Density Probability Distribution in Compressible Isothermal Turbulence: Solenoidal versus Compressive Forcing
• A High Order Godunov Scheme with Constrained Transport and Adaptive Mesh Refinement for Astrophysical MHD
• HOP: A New Group-Finding Algorithm for N-body Simulations
• Star formation through gravitational collapse and competitive accretion
• Turbulent molecular clouds
• The stellar mass spectrum from non-isothermal gravoturbulent fragmentation
• The Importance of Radiative Feedback for the Stellar Initial Mass Function
• Collapse of a Molecular Cloud Core to Stellar Densities: The First Three-Dimensional Calculations
• The Interplay of Magnetic Fields, Fragmentation and Ionization Feedback in High-Mass Star Formation
• Importance of the Initial Conditions for Star Formation - I. Cloud Evolution and Morphology
• The Stellar IMF, Core Mass Function, & The Last-Crossing Distribution
• Towards a more realistic sink particle algorithm for the RAMSES code
• Formation Scenario for Wide and Close Binary Systems
• The efficiency of star formation in clustered and distributed regions
• The Virial Balance of Clumps and Cores in Molecular Clouds
• The statistical properties of stars and their dependence on metallicity: the effects of opacity
• The Origin and Universality of the Stellar Initial Mass Function
• Star Formation in Self-Gravitating Turbulent Fluids
• Testing Larson's relationships in massive clumps
• Simulations of protostellar collapse using multigroup radiation hydrodynamics. II. The second collapse
• Protostellar Collapse Induced by Compression
• On the Power-Law Tail in the Mass Function of Protostellar Condensations and Stars
• The Necessity of Feedback Physics in Setting the Peak of the Initial Mass Function
• Stellar mass spectrum within massive collapsing clumps II. Thermodynamics and tidal forces of the first Larson core
• Formation of proto-cluster: a virialized structure from gravo-turbulent collapse I. Simulation of cluster formation in collapsing molecular cloud
• Stellar mass spectrum within massive collapsing clumps I. Influence of the initial conditions
• Bondi-Hoyle-Littleton accretion and the upper mass stellar IMF
• What Physics Determines the Peak of the IMF? Insights from the Structure of Cores in Radiation-Magnetohydrodynamic Simulations
• The FRIGG project: From intermediate galactic scales to self-gravitating cores
• A grid of 1D low-mass star formation collapse models
• The MLP Distribution: A Modified Lognormal Power-Law Model for the Stellar Initial Mass Function
• The core and stellar mass functions in massive collapsing filaments
• 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
• Radiation Hydrodynamics Simulations of Spherical Protostellar Collapse for Very Low Mass Objects

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• What is the role of stellar radiative feedback in setting the stellar mass spectrum?
• The IMF and multiplicity of stars from gravity, turbulence, magnetic fields, radiation and outflow feedback
• Multi-scale view of star formation in IRAS 21078+5211: From clump fragmentation to disk wind
• How magnetic field and stellar radiative feedback influences the collapse and the stellar mass spectrum of a massive star forming clump
• On the emergent System Mass Function: the contest between accretion and fragmentation
• On the origin of the peak of the stellar initial mass function: exploring the tidal screening theory
• Environmental variation of the low-mass IMF
• Variation of the low-mass end of the stellar initial mass function with redshift and metallicity
• Regulation of star formation by large scale gravito-turbulence
• W51North: A protocluster emerging out of a thermally inhibited fragmenting cloud
• The influence of the cloud virial parameter on the initial mass function
• Wide-binary eccentricity distribution in young star clusters: dependence on the binary separation and mass
• Do tides play a role in the determination of the pre-stellar core mass function?
• When did the initial mass function become bottom-heavy?
• Amplification and generation of turbulence during self-gravitating collapse