PHYSICS DISSERTATION DEFENSE: Alex Madurowicz
When built, the MAGIS-100 atom interferometer will be the largest in the world. But it's still missing a key component: a detailed camera. Stanford University
...Ph.D. Candidate: Alex Madurowicz
Research Advisor: Bruce Macintosh
Date: December 9, 2022
Time: 10 am
Location: PAB 102/103
Zoom Link: https://stanford.zoom.us/j/9842229268
Zoom Password: Email nickswan [at] stanford.edu for password.
Title: Universal Optical Instrumentation for Exoplanet Atmospheres
Abstract: Any astronomical inferences rely fundamentally on a model of the universe which incorporates relevant physical processes of the system in question. These models enable experimentation in otherwise inaccessible environments by providing a fictitious copy of the universe in which researchers can control the initial conditions or governing equations to disentangle cause and effect. An increasing number of experiments rely on astrophysical objects as essential components in the instrumentation, with various physical mechanisms forming the operating principle through which inferences are ultimately drawn. This has blurred the preexisting conventions which distinguish the human constructed instrumentation from the environment in which they operate as well as the objects under investigation. I aspire to dissolve these conventions entirely. A complete understanding of astrophysical instrumentation will require a hierarchical modeling strategy which incorporates all relevant physical processes over all scales to connect observations to inferences.
To support this perspective, I will connect results from three instrument studies and one observational study in the field of exoplanetary direct imaging to the overarching theme. Analysis of optical propagation through the turbulent atmosphere of the Earth demonstrates a fundamental limitation to single-deformable-mirror adaptive optics systems such as the Gemini Planet Imager as a result of scintillation. At the other end of the optical path, turbulent mixing in exoplanetary atmospheres can result in chemical abundances of molecules such as carbon monoxide which depart from equilibrium expectations, changing the near-infrared colors of the planet. Finally, I discuss two unique instrument concepts, the starshade and the solar gravitational lens, which explore the power and limitations of unconventional instrumentation which may enable unprecedented observations of other worlds.
