CMB-S4 Detector Development & SPT AGN Monitoring System

Abstract

In this thesis, we summarize work in two main areas: the development of millimeter-wave detectors for next-generation Cosmic Microwave Background (CMB) experiments and an initial study pioneering the use of CMB experiments as monitors of Active Galactic Nuclei (AGN). In the area of detector development, we describe two different projects: The initial room temperature measurements that resulted in the desired geometry for our antennae and the results from a simple device designed to characterize low-loss microstrips at 150 GHz, that helped identify necessary parameters for further testing of future loss devices. For the AGN monitoring, we present the results of a pilot study where we used data from the SPTpol camera on the South pole Telescope (SPT), which was designed to observe the CMB at arcminute and larger angular scales. We describe an initial search for evidence of correlated variability between SPTpol (150 GHz), SMARTS (Optical R-band) and Fermi (gamma-rays) observations. This work is paving the way for AGN monitoring with current and upcoming CMB experiments like SPT-3G, SO, and CMB-S4, including multi-wavelength variability studies with upcoming facilities such as VRO-LSST.