On August 8, Sanah Bhimani successfully defended the thesis “From Site to First Light: OCS Deployment and Defining Detector Quality Metrics for the Simons Observatory SAT-MF1” (advisor: Laura Newburgh).
Bhimani’s next position will be a postdoc at the University of Chicago, working with the Simons Observatory but with more of an instrument focus, as well as continuing time-domain data analysis.
Thesis Abstract:
The Simons Observatory (SO) is a ground-based cosmic microwave background (CMB) experiment located in the Atacama Desert in Chile at an elevation of 5200 m. It consists of one 6 m Large Aperture Telescope and three 0.5 m Small Aperture Telescopes, designed to study the temperature and polarization anisotropies of the CMB. SO will probe the CMB over a wide range of angular scales at the highest polarization sensitivities achieved to date. The Observatory will seek definitive evidence for inflation, provide insights into dark matter candidates that may have been prevalent in the early universe, and improve measurements of ΛCDM cosmology. SO encompasses hundreds of hardware components simultaneously running at different readout rates, all separate from its 60,000 detectors on-sky. Here, I detail my contributions to the commissioning, operation, and calibration of SO, with a focus on SAT-MF1, the first of SO’s telescopes to achieve first light. I provide an overview of commissioning the Observatory Control System (OCS), SO’s data acquisition and control software, to the site for SAT-MF1. I also describe a clustering algorithm, developed using commissioning data, to define detector quality metrics and propose a method for making data quality cuts for SAT-MF1’s detectors. This algorithm, integrated into the data processing pipeline, is applied across all telescopes and detector wafers, and will aid in characterizing detector systematics across SO’s 6 frequency bands.
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