THE DYNAMICS OF THE LARGE-MAGELLANIC-CLOUD PERIPHERY - MASS LIMIT ANDPOLAR RING

Radial velocities of 759 carbon stars on the periphery of the LMC are used to determine the rotation curve from 3 to 12 kpc. After a peak of 42 km s(-1) at 4 kpc, the velocities decline to 35 km s(-1) at 6.5 kp c, suggesting that 90% of the LMC's matter lies inside this radius. Th e rising: velocities seen at larger radii are explained by particle-pa rticle N-body simulations as arising from tidal interactions between L MC and both the SMC and the Galaxy. For an inclination of 33 degrees t he mass contained within a 5 kpc radius is 6.2 +/- 0.9 x 10(9) M.. An upper limit on the LMC halo mass is determined.