The Central Velocity Distribution Function of Omega Centauri

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Session 74 -- Globular Clusters
Display presentation, Friday, January 14, 9:30-6:45, Salons I/II Room (Crystal Gateway)

[74.04] The Central Velocity Distribution Function of Omega Centauri

Patrick Seitzer (Univ of Michigan)

Precise radial velocities have been obtained for 870 red giant stars within 4 arcminutes of the center of the globular cluster Omega Centauri (NGC\ 5139) using the ARGUS multiple object echelle spectrometer at CTIO. The resulting distribution of radial velocities is analyzed to derive the line of sight velocity distribution function, and is compared with various models of relaxed star clusters. The truncation of the velocity function is due to the Galactic tidal field, and some hint of the form this truncation takes is available even with this small number of stars. Observations at two epochs are available for most of the stars and are used to constrain the fraction of binary stars.

Friday program listing