GALAXIES AND MASS: LENSING AND DYNAMICAL MEASUREMENTS FROM THE SDSS

摘要

Probing the relationship between galaxies and mass is a major goal of the Sloan Digital Sky Survey. In this contribution we describe measurements of galaxy-mass correlations using both lensing and dynamical probes. The observables we discuss include the projected mass density contrast measured in SDSS imaging data and luminous particle motions measured as part of the SDSS galaxy redshift survey. Both probes of mass are sensitive measures, varying significantly with galaxy luminosity for example. Interpreting these results is complex. As a first step, we obtain best fit model parameters for various toy models. This exercise reveals the importance of making the comparison between theory and observation at the observable level. We argue for the use of full simulations, including both large scale structure and galaxy formation prescriptions, in the interpretation of these measurements. We conclude with a first generation example of such a comparison.