On the Trail of the Most Massive Galaxy Clusters in the Observable Universe

Galaxy clusters are enormous reservoirs of galaxies, hot gas and mysterious 'dark' matter. The hot gas produces a signal at millimeter wavelengths. The most massive clusters produce the strongest signals. Such signals can be detected from clusters anywhere in the universe. The team used millimeter observations from a space mission to identify massive cluster candidates. They will obtain follow-up observations to confirm the cluster identifications. The clusters will be used to test models of how structures form in the universe. They will also be used to constrain cosmological parameters. Senior team members will train junior team members. The team will develop material in Spanish and present it in Spanish in Illinois schools. The team will also engage with underrepresented minorities in South Africa.

The team will conduct follow-up observations of candidate galaxy clusters discovered through the Sunyaev-Zeldovich (SZ) effect. Their extensive imaging and spectroscopy with ground-based facilities will yield confirmed clusters. These are expected to be at high redshift and have high SZ-determined masses. The team will use the clusters to (1) test the Lambda Cold Dark Matter model for structure formation in the universe and (2) improve constraints on cosmological parameters from galaxy cluster counts.