English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The dynamics of planetesimals plays an important role in planet formation,because their velocity distribution sets the growth rate to larger bodies. Whenplanetesimals form in protoplanetary discs, their orbits are nearly circularand planar due to the effect of gas drag. However, mutual close encounters ofthe planetesimals increase eccentricities and inclinations until an equilibriumbetween stirring and damping is reached. After disc dissipation, there is nomore gas drag and mutual close encounters as well as encounters with planetsstir the orbits again. The high number of planetesimals in protoplanetary discsrenders it difficult to simulate their dynamics by means of direct N-bodysimulations of planet formation. Therefore, we developed a novel method for thedynamical evolution of planetesimals that is based on following closeencounters between planetesimal-mass bodies and gravitational stirring byplanet-mass bodies. To separate the orbital motion from the close encounters,we employ a Hamiltonian splitting scheme as used in symplectic N-bodyintegrators. Close encounters are identified using a cell algorithm with linearscaling in the number of bodies. A grouping algorithm is used to create smallgroups of interacting bodies which are integrated separately. Our method allowssimulating a high number of planetesimals interacting through gravity andcollisions with low computational cost. The typical computational time is ofthe order of minutes or hours, up to a few days for more complex simulations,as compared to several hours or even weeks for the same setup with full N-body.The dynamical evolution of the bodies is sufficiently well reproduced. Thiswill make it possible to study the growth of planetesimals through collisionsand pebble accretion coupled to their dynamics for a much higher number ofbodies than previously accessible with full N-body simulations.

A close-encounter method for simulating the dynamics of planetesimals