Measuring the Sunyaev-Zel'dovich Effects with Current and Future Observatories

Abstract

Increasingly precise measurements of the cosmic microwave background (CMB) continue to shape our understanding of our universe's origin, evolution, and contents. Measurements with ground-based observatories like the Atacama Cosmology Telescope (ACT) and satellite missions such as Planck have been able to precisely constrain the 6-parameter cosmological constant (Λ) Cold Dark Matter (CDM) model of cosmology and probe the growth of structure over cosmic time. Future observatories like CCAT-prime and the Simons Observatory will produce higher signal-to-noise data sets covering large areas on the sky, which will enable unprecedented measurements of the CMB and the Sunyaev-Zel'dovich effects. This data will inform our theoretical models of galaxy evolution and feedback mechanisms, provide insight into dark energy, and constrain the sum of the neutrino masses. Pursuit of these science goals necessitates the deployment of large numbers of sensitive superconducting detectors in novel cryogenic receivers. In this thesis we present the design of a first light instrument for the Fred Young Submillimeter Telescope (FYST), Mod-Cam, which will be used to deploy the first light microwave kinetic inductance detector array for the CCAT-prime project. Mod-Cam will also serve as a single-module cryogenic testbed for Prime-Cam, the first-generation science instrument for the FYST. We discuss the cryogenic design, initial instrument modules, and science goals for the Prime-Cam receiver. Developing the superconducting detector and readout technologies for these upcoming experiments requires laboratory testing to tune the fabrication process to the required parameters. We present measurements of transition edge sensors (TESes) and superconducting films that informed the fabrication process for the Simons Observatory (SO), which will field ~70,000 TES bolometers in six spectral bands centered between 27 and 280 GHz, and CMB-S4, the future ground-based CMB project that will push measurements of the CMB to cosmic variance limits. We also measure the magnetic sensitivity of TESes and the superconducting quantum interference devices (SQUIDs) required to amplify and read out the TES signals, and discuss how these measurements inform the magnetic shielding requirements for successful deployment of the components for future observatories such as SO. Maps of the CMB from observations with ACT, which relies on AlMn TESes like the ones measured in this thesis, have been combined with data from Planck to yield maps with superior depth and resolution to either data product alone. By using these maps in conjunction with optical data from the Sloan Digital Sky Survey, we present increasingly precise measurements of the thermal and kinematic Sunyaev-Zel'dovich (SZ) effects. We compare independent estimates of halo optical depth from these effects to explore the potential for thermal SZ measurements to serve as input for the measurement of kinematic SZ pairwise velocity curves which can constrain cosmology. By probing the optical depth of these galaxy halos, we also probe their baryon content, and make progress towards defining an empirical relationship between optical depth and Compton-y. This relationship will inform simulations of galaxy evolution and enable future precise cosmological constraints.