Several researchers at MKI study extragalactic astrophysics, a broad category of research that includes observational studies of phenomena outside our own Milky Way Galaxy. Among the active topics of research are clusters of galaxies; composed of hundreds to thousands of galaxies and containing large amounts of hot gas and dark matter, these are the largest gravitationally bound structures in the universe. As such, they serve as rich targets to study astrophysical processes in the universe, including the formation of structure, chemical enrichment and evolution, and galaxy formation, evolution, and feedback. Since galaxy clusters form primarily through gravitational processes, the mass distribution of clusters as a function of redshift (distance) places useful constraints on cosmology. Understanding the astrophysics of clusters is crucial to eliminate biases due to non-gravitational processes.
Scientists at MKI are engaged in a variety of research projects targeting the astrophysics of galaxy clusters. These projects heavily use instruments with direct MKI involvement, such as the Chandra X-ray Observatory, the Suzaku X-ray Observatory, and the Magellan telescopes. Members of MKI are also engaged in work with the South Pole Telescope collaboration and researchers at other institutions in the US and abroad.