Presented by Nina Hatch
School of Physics and Astronomy, Unversity of Nottingham, UK
Thursday, April 16, 2015
4:00 P.M. in 169-336
Galaxy clusters are the largest collapsed structures in the Universe. They are used both as cosmological probes, and as laboratories for studying galaxy formation and evolution. In my talk I will discuss some recent theoretical work investigating the early-time (1 < z < 3) formation of these clusters. At this epoch the clusters were not the collapsed, virialized structures we see today. Instead we see their progenitors; a diffuse collection of small haloes that will merge over several billion years to form the cluster. The term "protocluster" is often used to describe this early state. I will use detailed semi-analytic models to discuss the difference between high-redshift clusters and protoclusters. I will then present some recent observations of protoclusters at z~2, revealing their complex structure for the first time, and show how the properties of the member galaxies are highly dependent on where they are located within this structure. Finally, I will show how these protoclusters can be used as laboratories for studying galaxy evolution during the epoch of peak star formation and AGN feedback.
JPL Contact: Daniel Stern (4-7264)