2017/11/22 by Diogo Belloni, Pavel Kroupa, Helio J. Rocha-Pinto +2 · 20 citations
Chemistry · Mathematics · Physics and Astronomy · #Astrophysics #Astrophysics and Star Formation Studies #Binary number #Mathematics #Molecular Spectroscopy and Structure #Molecular cloud #Physics #Population #RADIUS #Star cluster #Stars #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.1093/mnras/stx3034
published in Monthly Notices of the Royal Astronomical Society 474(3), 3740-3745 (Oxford University Press) · 6 pages, 2 figures; accepted for publication in MNRAS, minor changes made to the text after proofs
openalex publication_date 2017/11/22 · arxiv created 2017/12/02 · openalex created_date 2017/12/04 · arxiv updated 2017/12/05 · openalex updated_date 2026/08/05
Abstract In order to allow a better understanding of the origin of Galactic field populations, dynamical equivalence of stellar-dynamical systems has been postulated by Kroupa and Belloni et al. to allow mapping of solutions of the initial conditions of embedded clusters such that they yield, after a period of dynamical processing, the Galactic field population. Dynamically equivalent systems are defined to initially and finally have the same distribution functions of periods, mass ratios and eccentricities of binary stars. Here, we search for dynamically equivalent clusters using the mocca code. The simulations confirm that dynamically equivalent solutions indeed exist. The result is that the solution space is next to identical to the radius–mass relation of Marks & Kroupa, ( r\rm h/\rm pc )= 0.1+0.07-0.04 ( M\rm ecl/\rm M\odot )0.13± 0.04. This relation is in good agreement with the observed density of molecular cloud clumps. According to the solutions, the time-scale to reach dynamical equivalence is about 0.5 Myr which is, interestingly, consistent with the lifetime of ultra-compact H ii regions and the time-scale needed for gas expulsion to be active in observed very young clusters as based on their dynamical modelling.