Velocities and Washington photometry in Carina dSph

Magellan telescope MIKE spectroscopy establishes the existence of Carina stars to at least 4.5 times its central King limiting radius, rlim, and primarily along Carina's major axis.

To keep these stars bound to the dSph would require a global Carina mass-to-light ratio of M/L>=6300(M/L)_{sun}}. The MIKE velocities, supplemented with ~950 additional Carina field velocities from archived VLT+GIRAFFE spectra with r<~rlim, demonstrate a nearly constant Carina velocity dispersion (sigma_v_) to just beyond r=rlim and both a rising and a velocity shear at still larger radii. Together, the observational evidence suggests that the discovered extended Carina population represents tidal debris from the dSph.