2000/01/01 by Christian Boily, C. M. Boily, Boily, Christian
Physics and Astronomy · #Astro and Planetary Science #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0002428
Talk given at the Strasbourg meeting Massive Star Clusters in November 1999; 7 pages, 3 figures xv-8bit giffed and tarred (= 100Kbytes); newpasp style file included
openalex publication_date 2000/01/01 · arxiv created 2000/02/23 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Abstract. The evolution of rotating, isolated clusters of stars up to core-collapse is investigated with n-body numerical codes. The simulations start off from axisymmetric generalisations of King profiles, with added global angular momentum. In this contribution we report on results obtained for two sets of single-mass cluster simulations. These confirm the more rapid evolution of even mildly-rotating clusters. A model is presented with rotational energy comparable to ωCentauri’s; it reaches core-collapse in less than half the time required for non-rotating clusters. 1. Background Star clusters are self-gravitating Newtonian systems of choice where to brew complex gravitational dynamics (Meylan & Heggie 1997 for a review). Observations of old, globular, stellar clusters have led to the formulation of spherically symmetric dynamical models of equilibria. The most successful and universally studied one-integral spherical models are the King (1966) profiles. However, surveys of up to 100 Milky Way clusters have found small but significant departures from spherical symmetry (White & Shawl 1987): fits to their projected isophotes yield ellipticities <ǫ> ≡ 1 − <a/b> ≈ 0.07 ± 0.01. A study of 173 clusters in M31 found <ǫ> = 0.09 ± 0.04 (Staneva, Spassova & Golev 1996). Observations of young clusters in the Large Magellanic Cloud revealed isophotal contours with ellipticities as large as ǫ = 0.3 (Elson, Fall & Freeman 1987; Kontizas et al. 1990). This raises the possibility that clusters are formed as strongly flattened structures which then evolve towards rounder configurations