ON THE KINEMATIC SIGNATURE OF A CENTRAL GALACTIC BAR IN OBSERVED STARSAMPLES

A quasi-self-consistent model for a barred structure in the central re gions of our Galaxy is used to calculate the signature of such a triax ial structure on the kinematical properties of star samples. We argue that, because of the presence of a velocity dispersion, such effects a re much harder to detect in the stellar component than in the gas. It might be almost impossible to detect stellar kinematical evidence for a bar using only l-v diagrams if there is no a priori knowledge of the potential. Therefore, we propose some test parameters that can easily be applied to observed star samples and that also incorporate distanc es or proper motions. We discuss the diagnostic power of these tests a s a function of the sample size and the bar strength. We conclude that about 1000 stars would be necessary to diagnose triaxiality with some statistical confidence.