Superparticle Method for Simulating Collisions

Abstract

For problems in astrophysics, planetary science and beyond, numerical simulations are often limited to simulating fewer particles than in the real system. To model collisions, the simulated particles (aka superparticles) need to be inflated to represent a collectively large collisional cross section of real particles. Here we develop a superparticle-based method that replicates the kinetic energy loss during real-world collisions, implement it in an $N$-body code and test it. The tests provide interesting insights into dynamics of self gravitating collisional systems. They show how particle systems evolve over several free fall timescales to form central concentrations and equilibrated outer shells. The superparticle method can be extended to account for the accretional growth of objects during inelastic mergers.

accepted in ApJ

References in corpus (14)

• Streaming Instabilities in Protoplanetary Disks
• Protoplanetary Disk Turbulence Driven by the Streaming Instability: Non-Linear Saturation and Particle Concentration
• Forming Planetesimals in Solar and Extrasolar Nebulae
• Particle Clumping and Planetesimal Formation Depend Strongly on Metallicity
• Protoplanetary Disk Turbulence Driven by the Streaming Instability: Linear Evolution and Numerical Methods
• Dust Evolution and the Formation of Planetesimals
• Formation of Kuiper Belt Binaries by Gravitational Collapse
• Particle-Gas Dynamics with Athena: Method and Convergence
• Evidence for universality in the initial planetesimal mass function
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• Demographics of Planetesimals Formed by the Streaming Instability
• Binary Survival in the Outer Solar System
• The role of pebble fragmentation in planetesimal formation II. Numerical simulations
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Cited by in corpus (4)

• High Resolution Study of Planetesimal Formation by Gravitational Collapse of Pebble Clouds
• Collisional Growth Within the Solar System's Primordial Planetesimal Disk and the Timing of the Giant Planet Instability
• Raining Rocks: An analytical formulation for collision timescales in planetary systems
• Considering contact forces during the formation of planetesimals by gravitational collapse: mutual orbits, spin states, and shapes