VU Physics and Astronomy Colloquium

Friday, Feb. 7, at 3:30 PM in NSC 224. Join us for refreshments in the Planetarium at 3:05 PM.

"Galaxy Evolution in the Neighborhood"

Dr. L. Arielle Phillips
University of Notre Dame Dept. of Physics

The formation, evolution, and chemical composition of galaxies are influenced by their interactions with the circumgalactic medium and therefore the local cosmic environment. This intergalactic medium (IGM) is composed of extensive clusters, filaments, and sheets of galaxies with vast empty expanses (voids) between them. Increasingly detections of intergalactic absorption features in quasar spectra are coupled with follow-up galaxy redshift surveys of the absorber neighborhood. The availability and analysis of these systems as well as higher resolution large scale simulations compel us to revisit the theoretical picture of the baryons in the cosmic web. We use a modified computer vision algorithm to identify and extract structures in large-scale simulations. Our understanding of the physical properties and extent of IGM structures is enhanced by progressing beyond a threshold-based definition of the components of the IGM and leads to a clearer interpretation of their role in the evolution of galaxies and of their signature in current and future observations.