Abstract:

To what extent does the surrounding dark matter environment shape the observational properties of luminous galaxies? In an attempt to shed further light on this question, I will present early results from a lensing analysis undertaken in the COSMOS field (Scoville et al. 2006). Weak gravitational lensing techniques have the unique ability to probe the full dark matter distribution and to reveal how galaxies are related to their dark matter haloes. Using the galaxy-galaxy lensing technique, I have mapped dark matter around an ensemble of galaxies and groups of galaxies within the COSMOS field. Using the exqusite ACS imaging to classify galaxies according to their morphology, I will show that the dark matter environment does indeed play a role in shaping the galaxies that we observe. Measuring this connection is not only a powerful test of the CDM paradigm, but also provides an essential ingredient towards understanding the physics of galaxy formation.