dc.contributor.advisor | Woitke, Peter | |
dc.contributor.advisor | Rice, Ken | |
dc.contributor.author | Tilling, Ian | |
dc.date.accessioned | 2013-12-11T09:56:25Z | |
dc.date.available | 2013-12-11T09:56:25Z | |
dc.date.issued | 2013-11-28 | |
dc.identifier.uri | http://hdl.handle.net/1842/8271 | |
dc.description.abstract | Protoplanetary 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_US |
dc.contributor.sponsor | Science and Technology Facilities Council (STFC) | en_US |
dc.language.iso | en | en_US |
dc.publisher | The University of Edinburgh | en_US |
dc.relation.hasversion | Tilling et al., “Gas modelling in the disc of HD 163296”. In Astronomy& Astrophysics, 2011. | en_US |
dc.relation.hasversion | Kamp, Tilling, Woitke, Thi & Hogerheijde, “Radiation thermo-chemical models of protoplanetary disks: II. Line diagnostics”. In Astronomy & Astrophysics, 2010. | en_US |
dc.relation.hasversion | Woitke, 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_US |
dc.relation.hasversion | Kamp, 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_US |
dc.relation.hasversion | Mathews et al., “GAS in Protoplanetary Systems (GASPS). I. First results”. In Astronomy & Astrophysics, 2010. | en_US |
dc.relation.hasversion | Pinte et al., “The Herschel view of GAS in Protoplanetary Systems (GASPS). First comparisons with a large grid of models”. In Astronomy & Astrophysics, 2010. | en_US |
dc.relation.hasversion | Thi 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_US |
dc.relation.hasversion | Meeus et al., “Gas in the protoplanetary disc of HD 169142: Herschel’s view”. In Astronomy & Astrophysics, 2010. | en_US |
dc.subject | protoplanetary discs | en_US |
dc.subject | Herschel observations | en_US |
dc.subject | far-infrared emission lines | en_US |
dc.title | Physics and chemistry of gas in discs | en_US |
dc.type | Thesis or Dissertation | en_US |
dc.type.qualificationlevel | Doctoral | en_US |
dc.type.qualificationname | PhD Doctor of Philosophy | en_US |