Velocity Dispersion Profiles of Seven Dwarf Spheroidal Galaxies

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We present stellar velocity dispersion profiles for seven Milky Way dwarf spheroidal (dSph) satellite galaxies.

• We have measured 8394 line-of-sight velocities (+/- 2.5 km/s) for 6804 stars from high-resolution spectra obtained at the Magellan and MMT telescopes.
• We combine these new data with previously published velocities to obtain the largest available kinematic samples, which include more than 5500 dSph members.
• All the measured dSphs have stellar velocity dispersion of order 10 km/s that remains approximately constant with distance from the dSph center, out to and in some cases beyond the radius at which the mean surface brightness falls to the background level.