The kinematics of globular clusters in the Large Magellanic Cloud

Velocities have been determined for 35 globular clusters in the LMC. These data have been combined with data from other sources to give velocities for 59 clusters ranging in age from ≡10⁸ to ≡10¹⁰ yr. Clusters younger than ≡10⁹ yr form a flattened system having a low line-of-sight velocity dispersion (≡15 km s⁻¹), an amplitude for their rotation of 37±5 km s⁻¹, a galactocentric systemic velocity of 40±3 km s⁻¹, and a line of nodes in position angle 1°±5°. The older clusters are also flattened to a disklike system with an intrinsic line-of-sight dispersion of only 17 km s⁻¹, and a rotation amplitude of 41±4 km s⁻¹. Surprisingly both the systemic velocity at 26±2 km s⁻¹, and the position angle of the line of nodes at 41°±5 are very significantly different for these older clusters. This enigmatic situation resisted all attempts at a solution. The data for the oldest clusters suggest that there is no evidence for a kinematic halo population among the globular clusters in the LMC.