COMMISSIONING THE SPIDER-2 INSTRUMENT AND SPIDER-1 LOW-LEVEL ANALYSIS

Abstract

The SPIDER instrument is a balloon-borne polarimeter designed to measure the primordial B-mode polarization in the cosmic microwave background (CMB). Theories of the very early universe predict that physical processes in the first fraction of a second after the Big Bang sourced large gravitational waves. These are expected to have imprinted a particular polarization pattern when passing through the surface of last scattering.

If it exists, this signal is currently obscured by astrophysical foreground emissions, pre- dominantly synchrotron radiation (at low frequencies) and Galactic dust (at high frequencies). The Galactic dust foreground is particularly difficult to characterize in ground observations as the signal is swamped by atmospheric emissions above approximately 200 GHz. SPIDER observes at 36 km altitude, above 99% of the atmosphere, allowing us to achieve background-limited observations of the microwave sky in key bands.

The first SPIDER instrument was launched in January 2015 from McMurdo Station in Antarctica and contained six 95 and 150 GHz slot-antenna-coupled Transition-Edge Sensor (TES) arrays. SPIDER-2 will re-deploy three proven SPIDER-1 telescopes alongside three feedhorn-coupled 280 GHz TES receivers in December 2020.

This document presents the SPIDER-2 instrument, with a focus on the 280GHz receivers and their integration into the flight cryostat.

To achieve a signal detection, we need both sensitive, carefully designed instruments and innovative analysis techniques. The second part of this thesis is devoted to an overview of the CMB analysis pipeline and characterizing a complicated source of correlated noise in the SPIDER-1 data set. The aim of this analysis is to recover polarization signal at large angular scales.