Showing papers on "Mass segregation published in 1985"
TL;DR: The role of energy equipartition and mass segregation in spherical dynamical systems having a large number of mass species is examined in this article, where a series of computer simulations based on numerical integrations of the multicomponent Fokker-Planck equation is described.
Abstract: The role of energy equipartition and mass segregation in spherical dynamical systems having a large number of mass species is examined. The general requirements for equipartition and the conditions for various forms of equipartition to hold in gravitating systems are discussed. A series of computer simulations based on numerical integrations of the multicomponent Fokker-Planck equation is described. The results indicate that even local equipartition can occur temporarily near the center among all mass species even if the mass spectrum is very steep. It is also found that the evolved density distributions are not homologous, in contrast to previous assumptions, and that only the massive stars can be in approximate equipartition if the mass spectrum is not very steep. Therefore the kinetic temperature of most stars, which determines the structure of globular clusters, may differ from the temperature of the more readily observable luminous stars. A simple model for the stronger tendency equipartition among the more massive components is given. 17 references.
50 citations
TL;DR: A neutral hydrogen survey was carried out at Arecibo on 91 dwarf irregular galaxies, with morphological types SDM through Im, in and around the direction of the Virgo Cluster.
Abstract: A neutral hydrogen survey was carried out at Arecibo on 91 dwarf irregular galaxies, with morphological types Sdm through Im, in and around the direction of the Virgo Cluster. Only nine of these were found to be background galaxies, and 19 remain undetected, i.e., most of the candidate galaxies are indeed members of the Virgo Cluster or Supercluster. The distribution of positions and systemic velocities (compared with large spirals) shows no evidence for mass segregation. The H I depletion for dwarfs in the cluster core is only moderate, no more than for spirals. The magnitude-velocity width correlation is continous from spirls to dwarfs. Satistics on H I masses agree only partially with a simple stochastic star formation model.
9 citations
4 citations
01 Jan 1985
TL;DR: In this paper, six proposed Space Telescope programs involving globular clusters are described, including the detection of white dwarfs, the study of the faint end of the Population II luminosity function, the measurement of mass segregation, and the search for a cusp in the density distribution caused by core collapse or by a massive black hole.
Abstract: Six proposed Space Telescope programs involving globular clusters are described. The projects appropriate for galactic clusters are: the detection of white dwarfs, the study of the faint end of the Population II luminosity function, the measurement of mass segregation, and the search for a cusp in the density distribution caused by core collapse or by a massive black hole. The two programs that involve extragalactic globular clusters are: the determination of the luminosity function of clusters around different galaxies and the measurement of tidal radii of clusters surrounding elliptical galaxies.
4 citations
01 Jan 1985
TL;DR: In this paper, stationary analytical models for the structure of spherical stellar systems with several mass components are presented, and an observable kinematical effect of mass segregation is pointed out, and the evolution is simulated by increasing the central velocity of escape.
Abstract: We present stationary analytical models for the structure of spherical stellar systems with several mass components. Evolution is simulated by increasing the central velocity of escape. We compare our models to the results of numerical simulations. An observable kinematical effect of mass segregation is pointed out.