Particle splitting in smoothed particle hydrodynamics based on Voronoi diagram

Abstract

We present a novel method for particle splitting in smoothed particle hydrodynamics simulations. Our method utilizes the Voronoi diagram for a given particle set to determine the position of fine daughter particles. We perform several test simulations to compare our method with a conventional splitting method in which the daughter particles are placed isotropically over the local smoothing length. We show that, with our method, the density deviation after splitting is reduced by a factor of about two compared with the conventional method. Splitting would smooth out the anisotropic density structure if the daughters are distributed isotropically, but our scheme allows the daughter particles to trace the original density distribution with length scales of the mean separation of their parent. We apply the particle splitting to simulations of the primordial gas cloud collapse. The thermal evolution is accurately followed to the hydrogen number density of 10^12 /cc. With the effective mass resolution of ~10^-4 Msun after the multi-step particle splitting, the protostellar disk structure is well resolved. We conclude that the method offers an efficient way to simulate the evolution of an interstellar gas and the formation of stars.

arXiv comment9 pages, 11 figures, accepted for publication in MNRAS

References in corpus (15)

• The cosmological simulation code GADGET-2
• E pur si muove: Galiliean-invariant cosmological hydrodynamical simulations on a moving mesh
• GIZMO: A New Class of Accurate, Mesh-Free Hydrodynamic Simulation Methods
• Formation of the First Supermassive Black Holes
• One Hundred First Stars : Protostellar Evolution and the Final Masses
• Formation of Primordial Stars in a LCDM Universe
• Supermassive black hole binaries in gaseous and stellar circumnuclear discs: orbital dynamics and gas accretion
• Direct Formation of Supermassive Black Holes via Multi-Scale Gas Inflows in Galaxy Mergers
• Smoothed Particle Hydrodynamics with particle splitting, applied to self-gravitating collapse
• A Density Independent Formulation of Smoothed Particle Hydrodynamics
• Fragmentation and Evolution of Molecular Clouds. I: Algorithm and First Results
• Supernova dust formation and the grain growth in the early universe: The critical metallicity for low-mass star formation
• The Burst Mode of Accretion in Primordial Protostars
• Low-mass star formation triggered by early supernova explosions
• Radiative cooling implementations in simulations of primordial star formation

Cited by in corpus (13)

• FIRE-2 Simulations: Physics versus Numerics in Galaxy Formation
• Building up the Population III initial mass function from cosmological initial conditions
• Formation of massive black holes in rapidly growing pre-galactic gas clouds
• Supermassive Star Formation via Super Competitive Accretion in Slightly Metal-enriched Clouds
• Metal-poor star formation triggered by the feedback effects from Pop III stars
• Osaka Feedback Model: Isolated Disk Galaxy Simulations
• Gravitational collapse and the thermal evolution of low-metallicity gas clouds in the early Universe
• Cosmological DCBH formation sites hostile for their growth
• Are the Formation and Abundances of Metal-Poor Stars the Result of Dust Dynamics?
• Numerical dependencies of the galactic dynamo in isolated galaxies with SPH
• Does the structure of Pop III supernova ejecta affect the elemental abundance of extremely metal-poor stars?
• Disc fragmentation and oligarchic growth of protostellar systems in low-metallicity gas clouds
• Numerical Methods for Simulating Star Formation