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Physical Sciences and Mathematics Commons

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Series

Astrophysics and Astronomy

1997

Star clusters

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

The Effect Of The Galactic Spheroid On Globular Cluster Evolution, C Murali, Md Weinberg Jan 1997

The Effect Of The Galactic Spheroid On Globular Cluster Evolution, C Murali, Md Weinberg

Astronomy Department Faculty Publication Series

We study the combined effects of relaxation, tidal heating and binary heating on globular cluster evolution, exploring the physical consequences of external effects and examining evolutionary trends in the MilkyWay population. Our analysis demonstrates that heating on circular and low-eccentricity orbits can dominate cluster evolution. The results also predict rapid evolution on eccentric orbits either due to strong relaxation caused by the high densities needed for tidal limitation or due to efficient bulge shocking of low density clusters. The combination of effects leads to strong evolution of the population as a whole. For example, within the solar circle, tidally-limited 105M⊙ …


Globular Cluster Evolution In M87 And Fundamental Plane Ellipticals, C Murali, Md Weinberg Jan 1997

Globular Cluster Evolution In M87 And Fundamental Plane Ellipticals, C Murali, Md Weinberg

Astronomy Department Faculty Publication Series

The globular cluster population in M87 has decreased measurably through dynamical evolution caused by relaxation, binary heating and time-dependent tidal perturbation. For fundamental plane ellipticals in general, cluster populations evolve more rapidly in smaller galaxies because of the higher mass density. A simple evolutionary model reproduces the observed trend in specific frequency with luminosity for an initially constant relationship. Fits of theoretically evolved populations to M87 cluster data from McLaughlin et al. (1994) show the following: 1) dynamical effects drive evolution in the initial mass and space distributions and can account for the large core in the spatial profile as …


Evolution Of The Galactic Globular Cluster System, C Murali, Md Weinberg Jan 1997

Evolution Of The Galactic Globular Cluster System, C Murali, Md Weinberg

Astronomy Department Faculty Publication Series

We study the dynamical evolution of disk and halo globular clusters in the Milky Way using a series of Fokker-Planck calculations combined with parametric statistical models. Our sample of 113 clusters with velocity data is predicted to descend from an initial population of 250 clusters, implying more than a factor of two decrease in population size due to evolution. Approximately 200 of these clusters are in a halo component and 50 in a disk component. The estimated initial halo population follows a coreless R−3.38 density profile in good agreement with current estimates for the distribution of halo field stars. The …