Afghan, Qasim;
(2024)
Analysis of Cometary Dust Tail Structures.
Doctoral thesis (Ph.D), UCL (University College London).
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Abstract
Cometary dust tails can display a wide range of spectacular fine-scale structure. Despite the extensive literature on these structures, their formation mechanisms, as well as how these structures evolve over time, are still not fully understood. The focus of this thesis is the analysis of some of these dust tail structures in order to shed more light on their formation process, and on cometary dust behaviour in general. The Finson-Probstein model is used in this work to simulate cometary dust tails and overlay these simulated tails onto images. This enables direct comparison between and analysis of the imaged tails. The image data can then be plotted in several different parameter spaces, including pixel brightness, β and ejection time. This allows for more accurate and extensive analysis of these structures than chieved in many other studies. This method is first used to analyse the dust tail of C/2014 Q1 (PanSTARRS) and identify a new dust tail structure. This dust tail displayed a large ‘gap’ in its middle, corresponding to a period of 7 days of reduced dust ejection from the nucleus. This is the first time a dust tail ‘gap’ of this kind has been identified, and a similar feature has since been found in 5 other comets. The dust tail of C/2020 F3 (NEOWISE) was the brightest dust tail, as seen from Earth, for 13 years. Furthermore, the dust tail was highly structured. This thesis presents analysis of this dust tail, providing an overview of the many features seen in the tail and parameterizing them. A follow-up population study of the syndynic bands in 6 comets (including C/2020 F3) was performed and their attributes compared. These bands share many similarities across all 6 comets, with some exceptions, and there is strong evidence to suggest these bands form due to distinct dust populations based on dust composition and structure.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Analysis of Cometary Dust Tail Structures |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2024. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10190763 |
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