The connection between galaxies and their host environments

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New telescope facilities and dedicated surveys have resulted in enormous progress in extra-galactic astronomy and cosmology over the past two decades. While we have now tightly constrained many of the fundamental cosmological parameters that describe our universe, there are still many unanswered questions concerning the formation and evolution of galaxies and larger structures. My research team is interested in studying the assembly of galaxies and the connection between observed galaxies and their environments. In order to address these topics we will study the evolution of galaxies in galaxy groups and clusters as a function of cosmic time.****Most galaxies in the local universe do not live in isolation, but are clustered into systems called galaxy groups. This environment, intermediate in density between rich galaxy clusters and isolated galaxies, appears to play an important role in galaxy evolution. However, relatively few sizable samples of groups have been identified at large distances. Over the past few years my team has been actively engaged in studying a large sample of groups at intermediate distances in order to understand the role that this environment plays in the evolution of galaxies. We have learned that the observed properties of group member galaxies depend on the group environment in which we find them, but that environmental effects are subtle and require large samples and careful analysis. In particular we have found that the properties of galaxies in groups depend on the assembly history of their host group, which can be traced using the motions of observed member galaxies. ****Over the next five years I plan to work with my students to study the evolution of more distant group galaxies from an epoch when the universe was much younger and many systems were just forming. Our goal is to shed light on the physical mechanisms governing the evolution of galaxies over cosmic time. We hope to further understand the diversity of galaxies and their properties and how their host environments affects this diversity. To answer these questions we will push the limits of current astronomical observations and plan for surveys with the next generation of facilities.**