2008/06/24 by Andreas H. W. Küpper, Andreas H. W. Kuepper, Pavel Kroupa +1 · 48 citations
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Binary star #Cluster (spacecraft) #Galaxy #Luminosity #Physics #RADIUS #Star cluster #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2008.13598.x
published in Monthly Notices of the Royal Astronomical Society 389(2), 889-902 (Oxford University Press) · 16 pages, 21 figures, accepted for publication in MNRAS
arxiv created 2008/06/24 · openalex publication_date 2008/08/06 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A novel way of looking at the evolution of star clusters is presented here. With a dynamical temperature, given by the mean kinetic energy of the cluster stars, and a dynamical luminosity, which is defined as the kinetic energy of the stars leaving the cluster in analogy to the energy of photons emitted by a star, the dissolution of star clusters is studied using a new dynamical temperature–luminosity diagram for star clusters. The investigation contains a parameter-space study of open clusters of up to N= 32 768 single-mass stars with different initial density distributions, half-mass radii, tidal conditions and binary fractions. The clusters show a strong correlation between dynamical temperature and dynamical luminosity and most of the investigated cluster families share a common sequence in such a dynamical temperature–luminosity diagram. Deviations from this sequence are analysed and discussed. After core collapse, the position of a cluster within this diagram can be defined by three parameters: the mass; the tidal conditions and the binary fraction. Due to core collapse all initial conditions are lost and the remaining stars adjust to the given tidal conditions. Binaries as internal energy sources influence this adjustment. A further finding concerns the Lagrange radii of star clusters: Throughout the investigated parameter space nearly all clusters show a constant half-mass radius for the time after core collapse until dissolution. Furthermore, the ratio of half-mass radius to tidal radius evolves on to a common sequence which only depends on the mass left in the cluster.