Probing the Large-Scale Structure of the Universe with the Simons Observatory

The cosmic microwave background (CMB), relic light from the period of recombination, is a powerful probe of fundamental physics; its polarization signature constrains the energy scale of cosmic inflation, while weak gravitational lensing of its photons measures large-scale structure in the Universe. At the Simons Observatory, a CMB research facility located in the Atacama Desert of northern Chile, we are measuring this light with extraordinary sensitivity in order to investigate these science goals. The observatory’s three 0.42 m small-aperture telescopes are searching for signs of cosmic inflation, while its 6 m large-aperture telescope is investigating a number of probes ranging from bounding the sum of the masses of neutrinos to searching for Solar System objects. This talk will discuss how the CMB’s rich science content has motivated the design of the Simons Observatory. It will then introduce the microwave frequency multiplexing system for the telescopes, which allows for low-noise readout of the roughly 100,000 superconducting transition-edge sensors which have been deployed across the observatory’s instruments to enable their cutting-edge sensitivity. The talk will also present studies of systematic signal contaminants in the observatory’s data and associated mitigation strategies, before showing work towards early weak lensing reconstruction results from the telescope’s first phase of operations.