9960( 1) - 04/04/03 10:41 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9960 Version: 1 Check-in Date: 04-Apr-2003 10:40:43 1.Proposal Title: The Lenses Structure and Dynamics (LSD) Survey: mass distribution and stellar populations of high redshift E/S0 galaxies ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle AR 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Tommaso Treu California Institute of Technology CoI: Dr. Leon Koopmans Space Telescope Science Institute N ------------------------------------------------------------------------------------ 5. Abstract Massive early-type lens galaxies are a particularly powerful cosmological tool. On the one hand, measuring the evolution with redshift of their stellar population, internal mass density profile and orbital structure probes their formation process and therefore the standard paradigm (formation by mergers). On the other hand, if their mass density profile is known accurately enough, they can deliver accurate measurements of the Hubble constant (time delays) and the cosmological constant (lens statistics). To measure the mass distribution and the properties of the stellar populations of distant E/S0 galaxies, we have carefully selected a sample of 11 lenses (in the range z=0.04-1). Exquisite HST WFPC2 and NICMOS data are already available and we have obtained deep and spatially resolved spectra at the Keck Telescope. The sample includes 6 pressure supported spheroids and 5 galaxies with significant disks and/or partial rotational support. As we have already demonstrated in two cases (MG2016+112 and 0047-281) this unique combination of data probes the total mass distribution (lensing-HST), the spatial distribution of luminous matter (surface photometry-HST), and the mass density profile (kinematics-Keck). This allows us to tightly constrain the mass distribution and orbital structure of luminous and dark matter of E/S0 galaxies up to z=1, and therefore the formation mechanisms and the value of the cosmological parameters. Furthermore, the combination of multi-color HST images and spectra provides spatially resolved measures of metallicity and ages of the stellar populations, thus the oportunity to understand the origin of color gradients, a sensitive probe of formation mechanisms. We are seeking the necessary funds to conduct the analysis. ------------------------------------------------------------------------------------ 9960( 1) - 04/04/03 10:41 - [ 2] Summary Form for Proposal 9960 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category AR ------------------------------------------------------------------------------------------------------------------------------------