Encounters in the ONC - observing imprints of star-disc interactions

Abstract

The external destruction of protoplanetary discs in a clustered environment acts mainly due to two mechanisms: gravitational drag by stellar encounters and evaporation by strong stellar winds and radiation. If encounters play a role in disc destruction, one would expect that stars devoid of disc material would show unexpectedly high velocities as an outcome of close interactions. We want to quantify this effect by numerical simulations and compare it to observations. As a model cluster we chose the Orion Nebula Cluster (ONC). We found from the observational data that 8 to 18 stars leave the ONC with velocities several times the velocity dispersion. The majority of these high-velocity stars are young low-mass stars, among them several lacking infrared excess emission. Interestingly, the high-velocity stars are found only in two separate regions of the ONC. Our simulations give an explanation for the location of the high-velocity stars and provide evidence for a strong correlation between location and disc destruction. The high-velocity stars can be explained as the outcome of close three-body encounters; the partial lack of disc signatures is attributed to gravitational interaction. The spatial distribution of the high-velocity stars reflects the initial structure and dynamics of the ONC. Our approach can be generalized to study the evolution of other young dense star clusters, like the Arches cluster, back in time.

12 pages, 9 figures, 1 table, accepted for publication in A&A, adopted changes after review by editors

References in corpus (34)

• Embedded Clusters in Molecular Clouds
• The Initial Mass Function of Stars: Evidence for Uniformity in Variable Systems
• Disk Frequencies and Lifetimes in Young Clusters
• Toward Understanding Massive Star Formation
• The distance to the Orion Nebula
• Photoevaporation of Circumstellar Disks due to External FUV Radiation in Stellar Aggregates
• The Luminosity & Mass Function of the Trapezium Cluster: From B stars to the Deuterium Burning Limit
• Inverse Dynamical Population Synthesis and Star Formation
• Constraints on the Stellar/Sub-stellar Mass Function in the Inner Orion Nebula Cluster
• The Initial Mass Function of Low-Mass Stars and Brown Dwarfs in Young Clusters
• The Dynamical Properties of Stellar Systems in the Galactic Disc
• Early Evolution of Stellar Groups and Clusters: Environmental Effects on Forming Planetary Systems
• Destruction of protoplanetary disks in the Orion Nebula Cluster
• The Spectroscopically Determined Substellar Mass Function of the Orion Nebula Cluster
• The mass ratio distribution of B-type visual binaries in the Sco OB2 association
• Visual Binaries in the Orion Nebula Cluster
• A Near-Infrared L Band Survey of the Young Embedded Cluster NGC 2024
• SPITZER/IRAC-MIPS Survey of NGC2244: Protostellar Disk Survival in the Vicinity of Hot Stars
• The Rise and Fall of Debris Disks: MIPS Observations of h and chi Persei and the Evolution of Mid-IR Emission from Planet Formation
• Encounter-Triggered Disc Mass Loss in the ONC
• Star Formation in Space and Time: The Orion Nebula Cluster
• The photometric-amplitude and mass-ratio distributions of contact binary stars
• Deep 3.8 micron Observations of the Trapezium Cluster
• The Becklin-Neugebauer Object as a Runaway B Star, Ejected 4000 years ago from the theta^1C system
• The distance to the Orion Nebula Cluster
• Possible Molecular Spiral Arms in the Protoplanetary Disk of AB Aur
• The Fate of Discs around Massive Stars in Young Clusters
• Stellar Encounters with Massive Star-Disk Systems
• Capture Formed Binaries via Encounters with Massive Protostars
• Gravitational Instabilities induced by Cluster Environment? - The encounter-induced angular momentum transfer in discs
• Constraints on Inner Disk Evolution Timescales: A Disk Census of the eta Chamaeleontis Young Cluster
• Binary Capture Rates for Massive Protostars
• Quasi-binarity of massive stars in young dense clusters - the case of the ONC
• Cluster-assisted accretion for massive stars

Cited by in corpus (24)

• The Kinematics of the Scorpius-Centaurus OB Association from Gaia DR1
• The dynamical evolution of multi-planet systems in open clusters
• Short dissipation times of proto-planetary discs - an artifact of selection effects?
• Do binaries in clusters form in the same way as in the field?
• Early evolution of the birth cluster of the solar system
• External photoevaporation of circumstellar disks constrains the timescale for planet formation
• Characterizing the dynamical state of star clusters from snapshots of their spatial distributions
• Can habitable planets form in clustered environments?
• Strong effect of the cluster environment on the size of protoplanetary discs?
• Runaway and walkaway stars from the ONC with Gaia DR2
• Dynamics versus structure: breaking the density degeneracy in star formation
• The evolution of binary populations in cool, clumpy star clusters
• Disks in the Arches cluster -- survival in a starburst environment
• Rapid destruction of protoplanetary discs due to externalphotoevaporation in star-forming regions
• Dynamical evolution of star forming regions - II. Basic kinematics
• Mass transfer between debris discs during close stellar encounters
• Photoevaporation and spatial variation of grain sizes in Orion 114-426
• The dynamical evolution of low-mass hydrogen-burning stars, brown dwarfs and planetary-mass objects formed through disc fragmentation
• Far and extreme ultraviolet radiation fields and consequent disc destruction in star-forming regions
• Does the mass distribution in discs influence encounter-induced losses in young star clusters?
• Unbound stars hold the key to young star cluster history
• Time-domain study of the young massive cluster Westerlund 2 with the Hubble Space Telescope. I
• Double trouble: Gaia reveals (proto)-planetary systems that may experience more than one dense star-forming environment
• The effects of supernovae on the dynamical evolution of binary stars and star clusters