Revisiting the universality of (multiple) star formation in present-day star formation regions

Abstract

Populations of multiple stars inside clustered regions are known to change through dynamical interactions. The efficiency of binary disruption is thought to be determined by stellar density. King and collaborators recently investigated the multiplicity properties in young star forming regions and in the Galactic field. They concluded that stellar density-dependent modification of a universal initial binary population (the standard or null hypothesis model) cannot explain the observations. We re-visit their results, analyzing the data within the framework of different model assumptions, namely non-universality without dynamical modification and universality with dynamics. We illustrate that the standard model does account for all known populations if regions were significantly denser in the past. Some of the effects of using present-day cluster properties as proxies for their past values are emphasized and that the degeneracy between age and density of a star forming region can not be omitted when interpreting multiplicity data. A new analysis of the Corona Australis region is performed within the standard model. It is found that this region is likely as unevolved as Taurus and an initial density of $\approx 190M_{\odot }p{c}^{-3}$ is required to produce the presently observed binary population, which is close to its present-day density.

accepted for publication in MNRAS; 12 pages; 4 figures; 3 tables

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Cited by in corpus (10)

• The formation of NGC 3603 young starburst cluster: "prompt" hierarchical assembly or monolithic starburst?
• Search for associations containing young stars (SACY). V. Is multiplicity universal? Tight multiple systems
• The state of globular clusters at birth II: primordial binaries
• Dynamics versus structure: breaking the density degeneracy in star formation
• The initial mass function and star formation law in the outer disc of NGC 2915
• Long-term stability of planets in and around binary stars
• New binaries in the epsilon Cha association
• Using binary statistics in Taurus-Auriga to distinguish between brown dwarf formation processes
• Unbound stars hold the key to young star cluster history
• Pairing function of visual binary stars