The internal structure of high-Z E/S0 galaxies from LSD

Abstract

We summarize results from the first year of the Lenses Structure and Dynamics Survey (LSD). Using the Echelle Imager and Spectrograph at the Keck-II Telescope, we have measured spatially resolved velocity dispersion profiles of a sample of distant (up to z=1) early-type galaxies that are gravitational lenses. By combining lensing and dynamical analyses we can set firm limits on the dark matter density profile, the controversial inner slope of the dark matter halo, the mass-to-light ratio of the luminous component, the total mass distribution, and on the velocity ellipsoid by breaking the mass anisotropy-relation. The implications of these measurements in terms on the epoch and mechanism of formation of E/S0 galaxies and of the value of the Hubble constant are briefly discussed.

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