Comets and Centaurs are icy remnants from the formation of the solar system. Analyzing the physical properties of their nuclei and their production rates can serve as powerful tools for tracing primitive solar system material. The four research projects in this dissertation examine these properties in comets and Centaurs. The first project focuses on observations of main belt comet 176P/LINEAR that were obtained with the Kepler space telescope. Optical lightcurves were used to constrain models of the nucleus's spin pole axis, shape and activity level. The second project used millimeter-wavelength spectra from the Arizona Radio Observatory Submillimeter Telescope and infrared photometry of Spitzer images to derive production rates of CO and CO2 from Oort Cloud comet C/2016 R2 (PANSTARRS). The third project is a compendium of CO, CO2, and H2O production rates in more than 25 comets and Centaurs that were obtained with a variety of space-based and ground-based telescopes and which were analyzed to test models of comet formation and evolution. CO, CO2, and H2O are the most abundant molecules observed in comets. The combination of these three molecules are likely the largest sources of elemental oxygen in the gas comae of comet and therefore a close approximation of the oxygen released in the comae. One key result of the survey is that CO/CO2 production rate ratios appear largely heliocentric dependent, with more CO produced the farther the comet is from the Sun. One exception is dynamically new comets which typically produce more CO2 than CO which is in predicted by models of significant cosmic-ray processing over time. The fourth project produced the first CO2 detection in a Centaur (39P/Oterma), which shows significant differences between the CO/CO2 in 39P and 29P, another Centaur, which may be partly due to different heating and processing histories.
| Identifer | oai:union.ndltd.org:ucf.edu/oai:stars.library.ucf.edu:etd2020-2887 |
| Date | 01 January 2023 |
| Creators | Harrington, Olga |
| Publisher | STARS |
| Source Sets | University of Central Florida |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Electronic Theses and Dissertations, 2020- |
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