Title:Joint mass and anisotropy modeling of dwarf spheroidals

Abstract:
Assuming spherical symmetry, smoothness and dynamical equilibrium, we model the distribution in 
projected phase space of well over 1000 stars in several of the major dwarf spheroidal galaxies orbiting the 
Milky Way, using the new MAMPOSSt algorithm. This gives us important constraints on the radial profiles 
of total mass and velocity anisotropy. For a better insight on the parameterizations of these two profiles, we 
precede our analysis with simpler models of the line-of-sight velocity dispersion profile as well as both mass 
and anisotropy inversions. We will compare with a similar analysis of a giant elliptical traced by over 500 
planetary nebulae, and discuss the different formation mechanisms of dwarf spheroidals and giant 
ellipticals.