Stellar and substellar initial mass function: a model that implements gravoturbulent fragmentation and accretion

Abstract

In this work, we derive the stellar initial mass function (IMF) from the superposition of mass distributions of dense cores, generated through gravoturbulent fragmentation of unstable clumps in molecular clouds (MCs) and growing through competitive accretion. MCs are formed by the turbulent cascade in the interstellar medium at scales L from 100 down to ~0.1 pc. Their internal turbulence is essentially supersonic and creates clumps with a lognormal distribution of densities n. Our model is based on the assumption of a power-law relationship between clump mass and clump density: n~m^x, where x is a scale-free parameter. Gravitationally unstable clumps are assumed to undergo isothermal fragmentation and produce protostellar cores with a lognormal mass distribution, centred around the clump Jeans mass. Masses of individual cores are then assumed to grow further through competitive accretion until the rest of the gas within the clump is being exhausted. The observed IMF is best reproduced for a choice of x=0.25, for a characteristic star formation timescale of ~5 Myr, and for a low star formation efficiency of ~10 %.

11 pages, 7 figures; accepted for publication in MNRAS

References in corpus (16)

• Slow Star Formation in Dense Gas: Evidence and Implications
• The Statistics of Supersonic Isothermal Turbulence
• Analytical theory for the initial mass function: CO clumps and prestellar cores
• The Density Probability Distribution in Compressible Isothermal Turbulence: Solenoidal versus Compressive Forcing
• Star formation through gravitational collapse and competitive accretion
• The Effects of Radiative Transfer on Low-Mass Star Formation
• On the Rapid Collapse and Evolution of Molecular Clouds
• Gravitational fragmentation and the formation of brown dwarfs in stellar clusters
• Six Myths on the Virial Theorem for Interstellar Clouds
• The Power Spectrum of Supersonic Turbulence in Perseus
• The Arches Cluster Mass Function
• On the Constancy of the Characteristic Mass of Young Stars
• The Origin of the Arches Stellar Cluster Mass Function
• Clump Lifetimes and the Initial Mass Function
• The relationship between the prestellar core mass function and the stellar initial mass function
• The star formation efficiency and its relation to variations in the initial mass function

Cited by in corpus (20)

• The Star Formation Rate of Turbulent Magnetized Clouds: Comparing Theory, Simulations, and Observations
• On the Star Formation Efficiency of Turbulent Magnetized Clouds
• The stellar and sub-stellar IMF of simple and composite populations
• The link between turbulence, magnetic fields, filaments, and star formation in the Central Molecular Zone cloud G0.253+0.016
• The Stellar IMF, Core Mass Function, & The Last-Crossing Distribution
• On the evolution of the density pdf in strongly self-gravitating systems
• A General Theory of Turbulent Fragmentation
• Star formation efficiency as a function of metallicity: from star clusters to galaxies
• Mapping the core mass function to the initial mass function
• Why Do Stars Form In Clusters? An Analytic Model for Stellar Correlation Functions
• Star Formation in Molecular Clouds
• Statistical link between the structure of molecular clouds and their density distribution
• Mass-density relationship in molecular cloud clumps
• Are the Formation and Abundances of Metal-Poor Stars the Result of Dust Dynamics?
• Star formation in IRDC G31.97+0.07
• On the Coagulation and Size Distribution of Pressure Confined Cores
• On turbulent fragmentation and the origin of the stellar IMF
• Turbulence and its connection to episodic accretion in binary YSOs
• Random fragmentation of turbulent molecular clouds lying in the central region of giant galaxies
• Modeling of molecular clouds with formation of prestellar cores