On encounter rates in star clusters

Abstract

Close encounters between stars in star forming regions are important as they can perturb or destroy protoplanetary discs, young planetary systems, and stellar multiple systems. We simulate simple, viralised, equal-mass $N$-body star clusters and find that both the rate and total number of encounters between stars varies by factors of several in statistically identical clusters due to the stochastic/chaotic details of orbits and stellar dynamics. Encounters tend to rapidly `saturate' in the core of a cluster, with stars there each having many encounters, while more distant stars have none. However, we find that the fraction of stars that have had at least one encounter within a particular distance grows in the same way (scaling with crossing time and half-mass radius) in all clusters, and we present a new (empirical) way of estimating the fraction of stars that have had at least one encounter at a particular distance.

arXiv comment12 pages, 5 figures, 4 tables

References in corpus (19)

• Embedded Clusters in Molecular Clouds
• Disk Frequencies and Lifetimes in Young Clusters
• High Resolution Submillimeter Constraints on Circumstellar Disk Structure
• Infrared L Band Observations of the Trapezium Cluster: A Census of Circumstellar Disks and Candidate Protostars
• A Near-Infrared L Band Survey of the Young Embedded Cluster NGC 2024
• The effects of dynamical interactions on planets in young substructured star clusters
• The formation of permanent soft binaries in dispersing clusters
• Tidally induced brown dwarf and planet formation in circumstellar discs
• The tidal disruption of protoplanetary accretion discs
• Binaries in star clusters and the origin of the field stellar population
• Characterizing a cluster's dynamic state using a single epoch of radial velocities
• Close Stellar Encounters in Young, Substructured, Dissolving Star Clusters: Statistics and Effects on Planetary Systems
• Induced planet formation in stellar clusters - a parameter study of star-disk encounters
• Multiplicity in Early Stellar Evolution
• Evolution of circumstellar discs in young star-forming regions
• Creating retrogradely orbiting planets by prograde stellar fly-bys
• Disc truncation in embedded star clusters: Dynamical encounters versus face-on accretion
• Planet population synthesis: The role of stellar encounters
• Close encounters: How stellar flybys shape planet-forming discs

Cited by in corpus (2)

• On the survivability of a population of gas giant planets on wide orbits
• Warps survive beyond fly-by encounters in protoplanetary disks. RW Aur A as a case study