Cosmic shear, or atmosphere? Modeling the atmosphere for dark energy measurements with the Vera C. Rubin Observatory

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Abstract/Contents

Abstract
The Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) will image tens of billions of galaxies over ten years--a 100 times increase over previous surveys--enabling the most precise measurements of dark energy properties to date. Realizing the full potential of this powerful dataset requires an unprecedented understanding of observational effects that, if uncorrected, can bias the science results. One such source is the blurring of images due to optical turbulence in the atmosphere, which dominates the point-spread function (PSF) for ground-based instruments. This atmospheric effect imprints spatially correlated noise on scales (and with amplitudes) similar to the cosmological signal we will study: the spatial correlation of positions and shapes of galaxies on the plane of the sky due to gravitational lensing of light by the dark matter in the Universe. High-fidelity simulated astronomical images are an important tool in developing and measuring the performance of image-processing algorithms that will be needed to accurately and precisely account for sources of correlated noise such as the atmospheric PSF. This thesis presents a new simulation tool, psf-weather-station, that allows us to study and model the dependence of correlations in the atmospheric PSF on weather conditions at any observatory by leveraging data from weather forecasting models. We use this tool to simulate the atmospheric PSF predicted for the Vera C. Rubin Observatory in Chile and make quantitative predictions of two-point correlation functions in the size and shape of the PSF that are used in analyses of cosmic shear. We also explore the temporal behaviour of the atmospheric PSF using high-resolution speckle images of stars, recorded near Rubin Observatory, and simulate similar observations using pfs-weather-station.

Description

Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource.
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2023; ©2023
Publication date 2023; 2023
Issuance monographic
Language English

Creators/Contributors

Author Hebert, Claire-Alice Caroline
Degree supervisor Burchat, Patricia
Thesis advisor Burchat, Patricia
Thesis advisor Moerner, William
Thesis advisor Roodman, Aaron
Degree committee member Moerner, William
Degree committee member Roodman, Aaron
Associated with Stanford University, School of Humanities and Sciences
Associated with Stanford University, Department of Applied Physics

Subjects

Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Claire-Alice Hebert.
Note Submitted to the Department of Applied Physics.
Thesis Thesis Ph.D. Stanford University 2023.
Location https://purl.stanford.edu/vc035yz3635

Access conditions

Copyright
© 2023 by Claire-Alice Caroline Hebert
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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