GRAPESPH with Fully Periodic Boundary Conditions: Fragmentation of Molecular Clouds

Abstract

A method of adapting smoothed particle hydrodynamics (SPH) with periodic boundary conditions for use with the special purpose device GRAPE is presented. GRAPE (GRAvity PipE) solves the Poisson and force equations for an N-body system by direct summation on a specially designed chip and in addition returns the neighbour list for each particle. Due to its design, GRAPE cannot treat periodic particle distributions directly. This limitation of GRAPESPH can be overcome by computing a correction force for each particle due to periodicity (Ewald correction) on the host computer using a PM-like method. This scheme is applied to study the fragmentation process in giant molecular clouds. Assuming a pure isothermal model, we follow the dynamical evolution in the interior of a molecular cloud starting from an Gaussian initial density distribution to the formation of selfgravitating clumps until most of the gas is consumed in these dense cores. Despite its simplicity, this model can reproduce some fundamental properties of observed molecular clouds, like a clump mass distribution of the form $dN/dm\propto m^n$, with $n-1.5$.

8 pages; LaTeX + 7 PS figures; accepted for publication in MNRAS; also available at http://www.mpia-hd.mpg.de/MPIA/Projects/THEORY/klessen/Preprints/p5.ps

Cited by in corpus (39)

• Gravitational Collapse in Turbulent Molecular Clouds. I. Gasdynamical Turbulence
• The SILCC (SImulating the LifeCycle of molecular Clouds) project: I. Chemical evolution of the supernova-driven ISM
• One-Point Probability Distribution Functions of Supersonic Turbulent Flows in Self-Gravitating Media
• The Formation of Stellar Clusters: Gaussian Cloud Conditions I
• The Formation of Stellar Clusters: Mass Spectra from Turbulent Molecular Cloud Fragmentation
• Planetary Nebulae: Observational Properties, Mimics, and Diagnostics
• The Formation of Stellar Clusters in Turbulent Molecular Clouds: Effects of the Equation of State
• Effects of the Equation of State on the Formation of Star Clusters
• Fragmentation of Molecular Clouds: The Initial Phase of a Stellar Cluster
• The Formation of Stellar Clusters: Gaussian Initial Conditions II
• N-body simulations of gravitational dynamics
• Evolving structures of star-forming clusters
• SWIFT: A modern highly-parallel gravity and smoothed particle hydrodynamics solver for astrophysical and cosmological applications
• SEREN - A new SPH code for star and planet formation simulations
• Jets and Tori in Proto-Planetary Nebulae
• Tree-based solvers for adaptive mesh refinement code FLASH - I: gravity and optical depths
• Tests of Spurious Transport in Smoothed Particle Hydrodynamics
• Ionizing Radiation in Smoothed Particle Hydrodynamics
• VINE -- A numerical code for simulating astrophysical systems using particles I: Description of the physics and the numerical methods
• Resolution requirements for simulating gravitational fragmentation using SPH
• Protostellar mass accretion rates from gravoturbulent fragmentation
• Understanding star formation in molecular clouds IV. Column density PDFs from quiescent to massive molecular clouds
• Protostellar Angular Momentum Evolution during Gravoturbulent Fragmentation
• The structure of self-gravitating clouds
• The first million years of the Sun: A calculation of formation and early evolution of a solar-mass star
• The Expansion Proper Motions of the Planetary Nebula NGC 6302 from HST imaging
• Flow-Driven Cloud Formation and Fragmentation: Results From Eulerian and Lagrangian Simulations
• Radio-continuum detections of Galactic Planetary Nebulae I. MASH PNe detected in large-scale radio surveys
• Low-ionization pairs of knots in planetary nebulae: physical properties and excitation
• Evolution of Class0 protostars: Models vs. Observations
• Jets and the shaping of the giant bipolar envelope of the planetary nebula KjPn 8
• The expansion proper motions of the extraordinary giant lobes of the planetary nebula KjPn 8 revisited
• The collimated outflows of the planetary nebula Hu1-2: proper motion and radial velocity measurements
• Number ratios of young stellar objects in embedded clusters
• Effects of clumping on temperature I: externally heated clouds
• Yukawa vs. Newton: gravitational forces in a cubic cosmological simulation box
• Fragmentation of vertically stratified gaseous layers: monolithic or coalescence-driven collapse
• Acceleration Method of Neighbor Search with GRAPE and Morton-ordering
• Star Formation from Turbulent Fragmentation