Cosmology via the Sunyaev-Zeldovich Effect

John Orlowski-Scherer, University of Pennsylvania


The study of clusters of galaxies is one of the most exciting and fruitful sub-fields of astronomy today; their number and distribution serve as powerful probes of the underlying cosmology, while their inner workings and structure are laboratories for astrophysics. In the Sunyaev-Zeldovich (SZ) effect photons from the Cosmic Microwave Background (CMB) inverse Compton scatter off of hot electrons in the intracluster media (ICM). The SZ effect directly probes the pressure of the ICM and is nearly redshift independent, and hence is a powerful tool for both detecting clusters and investigating their structure. Currently, CMB survey instruments are creating large, mass limited catalogs of galaxy clusters out to redshifts of ~1.75, and in the near future next generation CMB experiments will push these catalogs out to nearly a redshift of 3. Simultaneously, high resolution sub-millimeter experiments are mapping the structure of clusters, giving us insight into the astrophysics that govern these clusters and their interface to cosmology. In this thesis I detail work done in the design, integration, and testing of the Large Aperture Telescope Receiver (LATR) for the next generation CMB experiment, Simons Observatory (SO). The LATR will create field leading cluster catalogs, allowing us to test cosmology out to a redshift of 3. In particular this work will focus on simulations performed in the service of the LATR design process, as well as thermal validation tests that were done to validate the performance of the LATR. In addition, I report on the calibration of the mass-richness scaling relation for the Massive and Distant Clusters of Wise (MaDCoWS) cluster catalog using the current generation Atacama Cosmology Telescope (ACT). Finally, I report on the measurement by the MUSTANG-2 instrument of the thermodynamic state of a pair of X-ray cavities in the cluster MS 0735.6+7421 which were formed by the action of an active galactic nucleus. The mechanism of support for these cavities is not well understood, and the measurements we make of their thermodynamic state help to shed light on this topic.

Subject Area


Recommended Citation

Orlowski-Scherer, John, "Cosmology via the Sunyaev-Zeldovich Effect" (2022). Dissertations available from ProQuest. AAI29063488.