DYNAMICS OF THE GALACTIC GLOBULAR-CLUSTER NGC-3201

BV CCD frames have been used to derive surface brightness profiles for NGC 3201 which extend out to similar to 18'. A total of 857 radial ve locities with median precision similar or equal to 1 km s(-1) for 399 member giants have been used to trace the velocity dispersion profile out to 32.'1 (the approximate tidal radius determined from fits of sin gle-mass, isotropic King-Michie models to the cluster surface brightne ss profiles). The median difference in radial velocity for stars on ei ther side of an imaginary axis stepped through the cluster in 1 degree s increments shows a statistically significant maximum amplitude of 1. 22 +/- 0.25 km s(-1). We discuss several possible explanations of this result, including (1) cluster rotation, (2) preferential stripping of stars on prograde orbits near the limiting radius, (3) the projection of the cluster space velocity onto the plane of the sky, and (4) a sl ight drift in the velocity zero point. It is difficult to unambiguousl y identify the primary cause of the observed structure in the velocity field, however, and we suspect that all of the above processes may pl ay a role. The BV surface brightness profiles and radial velocities ha ve been modeled with both single- and multimass King-Michie models and nonparametric techniques. The corresponding density profiles and M/L profiles show good agreement over the interval 1.5 less than or simila r to R less than or similar to 10 pc, and both approaches suggest a st eady rise in M/L with distance from the cluster center. Due to the low cluster luminosity we are unable to place useful constraints on the a nisotropy of the velocity dispersion profile, although the global mass -to-light ratio is well constrained by the models: M/L(B) similar or e qual to M/L(V) similar or equal to 2.0 +/- 0.2 for the multimass and n onparametric models, compared to similar or equal to 1.65 +/- 0.15 for models having equal-mass stars. Our best-fit, multimass models have m ass function slopes of x similar or equal to 0.75 +/- 0.25, consistent with recent findings that the form of the mass function depends on th e position relative to the potential of the Galaxy.