Cosmic Evolution of Virial and Stellar Mass in Massive Early-Type Galaxies

Understand

We measure the average mass properties of a sample of 41 strong gravitational lenses at moderate redshift (z ~ 0.4 - 0.9), and present the lens redshift for 6 of these galaxies for the first time.

• Using the techniques of strong and weak gravitational lensing on archival data obtained from the Hubble Space Telescope, we determine that the average mass overdensity profile of the lenses can be fit with a power-law profile (Delta_Sigma prop.
• to R^{-0.86 +/- 0.16}) that is within 1-sigma of an isothermal profile (Delta_Sigma prop.
• to R^{-1}) with velocity dispersion sigma_v = 260 +/- 20 km/s.