Infant mortality in the hierarchical merging scenario: Dependency on gas expulsion timescales

Abstract

We examine the effects of gas expulsion on initially sub-structured and out-of-equilibrium star clusters. We perform N-body simulations of the evolution of star clusters in a static background potential before adjusting that potential to model gas expulsion. We investigate the impact of varying the rate at which the gas is removed, and the instant at which gas removal begins. Reducing the rate at which the gas is expelled results in an increase in cluster survival. Quantitatively, this dependency is approximately in agreement with previous studies, despite their use of smooth, and virialised initial stellar distributions. However, the instant at which gas expulsion occurs is found to have a strong effect on cluster response to gas removal. We find if gas expulsion occurs prior to one crossing time, cluster response is poorly described by any global parameters. Furthermore in real clusters the instant of gas expulsion is poorly constrained. Therefore our results emphasis the highly stochastic and variable response of star clusters to gas expulsion.

11 pages, 7 figures, Accepted to MNRAS, October 1st 2012

References in corpus (10)

• A Spitzer Survey of Young Stellar Clusters within One Kiloparsec of the Sun: Cluster Core Extraction and Basic Structural Analysis
• A comprehensive set of simulations studying the influence of gas expulsion on star cluster evolution
• Gas expulsion and the destruction of massive young clusters
• Dynamical mass segregation on a very short timescale
• Dynamics of Dense Cores in the Perseus Molecular Cloud
• The distinction between star clusters and associations
• The influence of residual gas expulsion on the evolution of the Galactic globular cluster system and the origin of the Population II halo
• The structures of embedded clusters in the Perseus, Serpens and Ophiuchus molecular clouds
• The Origin of the Gaussian Initial Mass Function of Old Globular Cluster Systems
• The shape of the initial cluster mass function: what it tells us about the local star formation efficiency

Cited by in corpus (35)

• Star Clusters Across Cosmic Time
• The Big Problems in Star Formation: the Star Formation Rate, Stellar Clustering, and the Initial Mass Function
• When Feedback Fails: The Scaling and Saturation of Star Formation Efficiency
• Globular cluster formation in the context of galaxy formation and evolution
• The Physics of Star Cluster Formation and Evolution
• Disruption of giant molecular clouds and formation of bound star clusters under the influence of momentum stellar feedback
• A model for the formation of stellar associations and clusters from giant molecular clouds
• Highly efficient star formation in NGC 5253 possibly from stream-fed accretion
• The formation of NGC 3603 young starburst cluster: "prompt" hierarchical assembly or monolithic starburst?
• The bound fraction of young star clusters
• How can young massive clusters reach their present-day sizes?
• Early evolution of embedded clusters
• Star Clusters in Evolving Galaxies
• Impact of a star formation efficiency profile on the evolution of open clusters
• A perfect starburst cluster made in one go: the NGC 3603 young cluster
• Great Balls of FIRE I: The formation of star clusters across cosmic time in a Milky Way-mass galaxy
• Close Stellar Encounters in Young, Substructured, Dissolving Star Clusters: Statistics and Effects on Planetary Systems
• Gas expulsion in highly substructured embedded star clusters
• The difficult early stages of embedded star clusters and the importance of the pre-gas expulsion virial ratio
• Flipping-up the field: gravitational feedback as a mechanism for young clusters dispersal
• How fast is mass-segregation happening in hierarchical formed embedded star clusters?
• Reaction of Massive Clusters to Gas Expulsion - The cluster density dependence
• Early-Forming Massive Stars Suppress Star Formation and Hierarchical Cluster Assembly
• Star Cluster Formation from Turbulent Clumps. II. Gradual Star Cluster Formation
• Formation of Very Young Massive Clusters and implications for globular clusters
• Hierarchical formation of Westerlund 1: a collapsing cluster with no primordial mass segregation?
• The star cluster survivability after gas expulsion is independent of the impact of the Galactic tidal field
• Hα to FUV ratios in resolved star forming region populations of nearby spiral galaxies
• Ionized Gas Motions and the Structure of Feedback Near a Forming Globular Cluster in NGC 5253
• Star Cluster Formation from Turbulent Clumps. I. The Fast Formation Limit
• Dynamical Ejections of Stars due to an Accelerating Gas Filament
• Unveiling the initial conditions of open star cluster formation
• TYCHO -- Realistically Simulating Exoplanets within Stellar Clusters I: Improving the Monte Carlo Approach
• Global survey of star clusters in the Milky Way VIII. Cluster formation and evolution
• Massive star clusters detected by JWST as natural birth places to form intermediate-mass black holes