Anisotropies in the Motions and Positions of the Galactic Globular Clusters

The velocity ellipsoid for 38 globular clusters with [Fe/H] <= -1.0 isderived and shown to be significantly anisotropic with major axis directedtowards low Galactic latitude. Principal axes of the spatial distribution ofdifferent groups of clusters are derived and compared with the velocityellipsoid. The metal poor cluster spatial distribution is significantlyflattened along an axis which coincides within the uncertainties with the majoraxis of the velocity ellipsoid. Given the observed steep age-metallicityrelation for metal poor clusters, one speculative interpretation of the data isthat an initially flattened filament underwent a relatively rapid initialtransverse collapse forming satellite galaxies and metal poor globular clusterswhile the protogalaxy collapsed and assembled more slowly along the filamentacquiring and/or redistributing angular momentum in the process.Comment: 10 pages, 1 figure, accepted for publication in ApJ Letter