{"id":{"repo_id":"cambridge","oai_identifier":"oai:www.repository.cam.ac.uk:1810/277655"},"canonical_url":"https://search.dev.ndltd.org/etd/cambridge/oai:www.repository.cam.ac.uk:1810/277655","repository":{"repo_id":"cambridge","name":"Cambridge University","base_url":"https://api.repository.cam.ac.uk/server/oai/request"},"display":{"title":"Protoplanetary discs across the stellar mass range","abstract":"In this thesis, I discuss two studies concerned with modelling protoplanetary discs around stars from different ends of the stellar mass range. In Chapters 1 and 2, I give an introduction to the field of protoplanetary discs, both from an observational and a modelling point of view, and describe the radiative transfer methods I have employed. In Chapter 3, I present my work regarding the disc around the Herbig Ae star HD 163296. I show the results of applying a new modelling technique to this disc: I combine SED modelling with fits to the CO snowline location and C$^{18}$O $J=2-1$ line profile from ALMA. I find that all of the modelling steps are crucial to break degeneracies in the disc parameter space. The use of all of these constraints favours a solution with a notably low gas-to-dust ratio ($g/d<20$). The only models with a more interstellar medium (ISM)-like $g/d$ require C$^{18}$O to be underabundant with respect to the ISM abundances and a significant depletion of sub-micron grains, which is not supported by scattered light observations. I propose that the technique can be applied to a range of discs and opens up the prospect of being able to measure disc dust and gas budgets without making assumptions about the $g/d$ ratio. In Chapter 4, I present my work on characterising the disc around the very low mass star V410 X-ray 1. Protoplanetary discs around such low mass stars offer some of the best prospects for forming Earth-sized planets in their habitable zones. The SED of V410 X-ray 1 is indicative of an optically thick and very truncated dust disc, with my modelling suggesting an outer radius of only 0.6 au. I investigate two scenarios that could lead to such a truncation, and find that the observed SED is compatible with both. The first scenario involves the truncation of both the dust and gas in the disc, perhaps due to a previous dynamical interaction or the presence of an undetected companion. The second scenario involves the fact that a radial location of 0.6 au is close to the expected location of the H$_2$O snowline in the disc. As such, a combination of efficient dust growth, radial migration, and subsequent fragmentation within the snowline leads to an optically thick inner dust disc and larger, optically thin outer dust disc. I find that a firm measurement of the CO $J=2-1$ line flux would distinguish between these two scenarios by enabling a measurement of the radial extent of gas in the disc. Many models I consider contain at least several Earth-masses of dust interior to 0.6 au, suggesting that V410 X-ray 1 could be a precursor to a system of tightly-packed inner planets, such as TRAPPIST-1. In Chapter 5, I summarise the work presented in this thesis, give an overview of future applications of the methods outlined in this dissertation, and an outlook on potential future projects.","abstract_html":"In this thesis, I discuss two studies concerned with modelling protoplanetary discs around stars from different ends of the stellar mass range. In Chapters 1 and 2, I give an introduction to the field of protoplanetary discs, both from an observational and a modelling point of view, and describe the radiative transfer methods I have employed. In Chapter 3, I present my work regarding the disc around the Herbig Ae star HD 163296. I show the results of applying a new modelling technique to this disc: I combine SED modelling with fits to the CO snowline location and C<span class=\"etd-inline-math\"><sup>18</sup></span>O $J=2-1$ line profile from ALMA. I find that all of the modelling steps are crucial to break degeneracies in the disc parameter space. The use of all of these constraints favours a solution with a notably low gas-to-dust ratio ($g/d&lt;20$). The only models with a more interstellar medium (ISM)-like $g/d$ require C<span class=\"etd-inline-math\"><sup>18</sup></span>O to be underabundant with respect to the ISM abundances and a significant depletion of sub-micron grains, which is not supported by scattered light observations. I propose that the technique can be applied to a range of discs and opens up the prospect of being able to measure disc dust and gas budgets without making assumptions about the $g/d$ ratio. In Chapter 4, I present my work on characterising the disc around the very low mass star V410 X-ray 1. Protoplanetary discs around such low mass stars offer some of the best prospects for forming Earth-sized planets in their habitable zones. The SED of V410 X-ray 1 is indicative of an optically thick and very truncated dust disc, with my modelling suggesting an outer radius of only 0.6 au. I investigate two scenarios that could lead to such a truncation, and find that the observed SED is compatible with both. The first scenario involves the truncation of both the dust and gas in the disc, perhaps due to a previous dynamical interaction or the presence of an undetected companion. The second scenario involves the fact that a radial location of 0.6 au is close to the expected location of the H<span class=\"etd-inline-math\"><sub>2</sub></span>O snowline in the disc. As such, a combination of efficient dust growth, radial migration, and subsequent fragmentation within the snowline leads to an optically thick inner dust disc and larger, optically thin outer dust disc. I find that a firm measurement of the CO $J=2-1$ line flux would distinguish between these two scenarios by enabling a measurement of the radial extent of gas in the disc. Many models I consider contain at least several Earth-masses of dust interior to 0.6 au, suggesting that V410 X-ray 1 could be a precursor to a system of tightly-packed inner planets, such as TRAPPIST-1. In Chapter 5, I summarise the work presented in this thesis, give an overview of future applications of the methods outlined in this dissertation, and an outlook on potential future projects.","abstract_has_math":true,"creators":["Boneberg, Dominika Maria Rita"],"institution":"University of Cambridge","degree_name":"Doctor of Philosophy (PhD)","degree_level":"Doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Clarke, Cathie J.","Ilee, John D."],"committee_chairs":[],"committee_members":[],"year":2018,"date_issued":"2018-07-21","date_published":"2018-07-21","updated_at":"2026-07-22T22:24:24Z","subjects":["astronomy","planet formation","protoplanetary discs","ALMA"],"languages":["en"],"rights":[],"rights_urls":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/c100149d-fb2d-49cd-b3fa-61a41ff2143f/download","https://www.rioxx.net/licenses/all-rights-reserved/"],"identifier_entries":[]},"links":{"outbound_url":"https://doi.org/10.17863/CAM.24991","outbound_label":"DOI","outbound_source":"dc:identifier.doi"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Clarke, Cathie J.","Ilee, John D."]},{"key":"dc:contributor.sponsor","label":"Sponsor","values":["STFC"]},{"key":"dc:creator","label":"Author","values":["Boneberg, Dominika Maria Rita"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2018-07-21"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cambridge"]},{"key":"dc:relation.isreferencedby.uri","label":"Dc Relation Isreferencedby URI","values":["https://www.repository.cam.ac.uk/handle/1810/277655"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["astronomy","planet formation","protoplanetary discs","ALMA"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/c100149d-fb2d-49cd-b3fa-61a41ff2143f/download","https://www.rioxx.net/licenses/all-rights-reserved/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.doi","label":"DOI","values":["10.17863/CAM.24991"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/c32cae5e-5ef3-41b7-a3f0-10498e9a038b/download"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["In this thesis, I discuss two studies concerned with modelling protoplanetary discs around stars from different ends of the stellar mass range. 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I propose that the technique can be applied to a range of discs and opens up the prospect of being able to measure disc dust and gas budgets without making assumptions about the $g/d$ ratio. In Chapter 4, I present my work on characterising the disc around the very low mass star V410 X-ray 1. Protoplanetary discs around such low mass stars offer some of the best prospects for forming Earth-sized planets in their habitable zones. The SED of V410 X-ray 1 is indicative of an optically thick and very truncated dust disc, with my modelling suggesting an outer radius of only 0.6 au. I investigate two scenarios that could lead to such a truncation, and find that the observed SED is compatible with both. The first scenario involves the truncation of both the dust and gas in the disc, perhaps due to a previous dynamical interaction or the presence of an undetected companion. The second scenario involves the fact that a radial location of 0.6 au is close to the expected location of the H$_2$O snowline in the disc. As such, a combination of efficient dust growth, radial migration, and subsequent fragmentation within the snowline leads to an optically thick inner dust disc and larger, optically thin outer dust disc. I find that a firm measurement of the CO $J=2-1$ line flux would distinguish between these two scenarios by enabling a measurement of the radial extent of gas in the disc. Many models I consider contain at least several Earth-masses of dust interior to 0.6 au, suggesting that V410 X-ray 1 could be a precursor to a system of tightly-packed inner planets, such as TRAPPIST-1. In Chapter 5, I summarise the work presented in this thesis, give an overview of future applications of the methods outlined in this dissertation, and an outlook on potential future projects."]},{"key":"dc:format.checksum.md5","label":"Dc Format Checksum Md5","values":["e744889654be811d5abeaf006888178e","87eda9de84448d1f82354d60eee3eb5f"]},{"key":"dc:title","label":"Title","values":["Protoplanetary discs across the stellar mass range"]}]}],"canonical_facts":{"dc:contributor.advisor":["Clarke, Cathie J.","Ilee, John D."],"dc:contributor.sponsor":["STFC"],"dc:creator":["Boneberg, Dominika Maria Rita"],"dc:date.issued":["2018-07-21"],"dc:description.abstract":["In this thesis, I discuss two studies concerned with modelling protoplanetary discs around stars from different ends of the stellar mass range. 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I propose that the technique can be applied to a range of discs and opens up the prospect of being able to measure disc dust and gas budgets without making assumptions about the $g/d$ ratio. In Chapter 4, I present my work on characterising the disc around the very low mass star V410 X-ray 1. Protoplanetary discs around such low mass stars offer some of the best prospects for forming Earth-sized planets in their habitable zones. The SED of V410 X-ray 1 is indicative of an optically thick and very truncated dust disc, with my modelling suggesting an outer radius of only 0.6 au. I investigate two scenarios that could lead to such a truncation, and find that the observed SED is compatible with both. The first scenario involves the truncation of both the dust and gas in the disc, perhaps due to a previous dynamical interaction or the presence of an undetected companion. The second scenario involves the fact that a radial location of 0.6 au is close to the expected location of the H$_2$O snowline in the disc. As such, a combination of efficient dust growth, radial migration, and subsequent fragmentation within the snowline leads to an optically thick inner dust disc and larger, optically thin outer dust disc. I find that a firm measurement of the CO $J=2-1$ line flux would distinguish between these two scenarios by enabling a measurement of the radial extent of gas in the disc. Many models I consider contain at least several Earth-masses of dust interior to 0.6 au, suggesting that V410 X-ray 1 could be a precursor to a system of tightly-packed inner planets, such as TRAPPIST-1. In Chapter 5, I summarise the work presented in this thesis, give an overview of future applications of the methods outlined in this dissertation, and an outlook on potential future projects."],"dc:format.checksum.md5":["e744889654be811d5abeaf006888178e","87eda9de84448d1f82354d60eee3eb5f"],"dc:identifier.doi":["10.17863/CAM.24991"],"dc:identifier.uri":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/c32cae5e-5ef3-41b7-a3f0-10498e9a038b/download"],"dc:language":["en"],"dc:publisher.institution":["University of Cambridge"],"dc:relation.isreferencedby.uri":["https://www.repository.cam.ac.uk/handle/1810/277655"],"dc:rights":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/c100149d-fb2d-49cd-b3fa-61a41ff2143f/download","https://www.rioxx.net/licenses/all-rights-reserved/"],"dc:subject":["astronomy","planet formation","protoplanetary discs","ALMA"],"dc:title":["Protoplanetary discs across the stellar mass range"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral"],"dc:type.qualificationname":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-22T22:24:24Z"}