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dc.contributor.advisorWoitke, Peteren
dc.contributor.advisorRice, Kenen
dc.contributor.authorTilling, Ianen
dc.date.accessioned2013-12-11T09:56:25Z
dc.date.available2013-12-11T09:56:25Z
dc.date.issued2013-11-28
dc.identifier.urihttp://hdl.handle.net/1842/8271
dc.description.abstractProtoplanetary discs set the initial conditions for planet formation. By combining observations with detailed modelling, it is possible to constrain the physics and chemistry in such discs. I have used the detailed thermo-chemical disc model ProDiMo to explore the characteristics of the gas in protoplanetary discs, particularly in Herbig Ae objects. I have assessed the ability of various observational data to trace the disc properties. This has involved a number of different approaches. Firstly I compute a series of disc models with increasing mass, in order to test the diagnostic powers of various emission lines, in particular as gas mass tracers. This approach is then expanded to a large multiparameter grid of ~ 10 5 disc models. I have helped to develop a tool for analysing and plotting the huge quantity of data presented by such a model grid. Following this approach I move on to a detailed study of the Herbig Ae star HD 163296, attempting to fit the large wealth of available observations simultaneously. These include new Herschel observations of the far-infrared emission lines, as well as interferometric CO observations and a large number of continuum data. This study addresses the topical issues of the disc gas/dust ratio, and the treatment of the disc outer edge. It explores the effects of dust settling, UV variability and stellar X-ray emission on the disc chemistry and line emission. There is possible evidence for gas-depletion in the disc of HD 163296, with the line emission enhanced by dust settling, which would indicate a later evolutionary stage for this disc than suggested by other studies. Finally, I work to improve the treatment of the gas heating/cooling balance in ProDiMo, by introducing a non-LTE treatment of the atomic hydrogen line transitions and bound-free continuum transitions. I explore the effects of this on the disc chemical and thermal structure, and assess its impact in terms of the observable quantities.en
dc.contributor.sponsorScience and Technology Facilities Council (STFC)en
dc.language.isoen
dc.publisherThe University of Edinburghen
dc.relation.hasversionTilling et al., “Gas modelling in the disc of HD 163296”. In Astronomy& Astrophysics, 2011.en
dc.relation.hasversionKamp, Tilling, Woitke, Thi & Hogerheijde, “Radiation thermo-chemical models of protoplanetary disks: II. Line diagnostics”. In Astronomy & Astrophysics, 2010.en
dc.relation.hasversionWoitke, Pinte, Tilling et al., “Continuum and line modelling of discs around young stars - I. 300000 disc models for HERSCHEL/GASPS”. In Monthly Notices of the Royal Astronomical Society, 2010.en
dc.relation.hasversionKamp, Woitke, Pinte, Tilling et al., “Continuum and line modeling of disks around young stars II. Line diagnostics for GASPS from the DENT grid”. In Astronomy & Astrophysics, 2011.en
dc.relation.hasversionMathews et al., “GAS in Protoplanetary Systems (GASPS). I. First results”. In Astronomy & Astrophysics, 2010.en
dc.relation.hasversionPinte et al., “The Herschel view of GAS in Protoplanetary Systems (GASPS). First comparisons with a large grid of models”. In Astronomy & Astrophysics, 2010.en
dc.relation.hasversionThi et al., “Herschel-PACS observation of the 10 Myr old T Tauri disk TW Hya. Constraining the disk gas mass”. In Astronomy & Astrophysics, 2010.en
dc.relation.hasversionMeeus et al., “Gas in the protoplanetary disc of HD 169142: Herschel’s view”. In Astronomy & Astrophysics, 2010.en
dc.subjectprotoplanetary discsen
dc.subjectHerschel observationsen
dc.subjectfar-infrared emission linesen
dc.titlePhysics and chemistry of gas in discsen
dc.typeThesis or Dissertationen
dc.type.qualificationlevelDoctoralen
dc.type.qualificationnamePhD Doctor of Philosophyen


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