Gas in young planet-forming and debris disks


Thesis Supervisor: Bill Dent




To understand how planetary systems are formed, we can study the structure, dynamics and chemical composition of gas-rich disks around very young stars. But almost all of these planet-forming disks are younger than a few million yrs; older systems were thought to contain only "dry" dusty debris and planets. Does that mean that all planet formation is over by ~10Myr?
Recently, a number of older debris disks have been discovered to contain gas. Are these unusually old protoplanetary disks or something else? Is planet formation or contamination still occurring, or are they participating in the Late Heavy Bombardment that affected our own Solar System at a few hundred Myr?

As part of a large team of about 30 astronomers in Europe and the US, we have used the Herschel far-infrared telescope to study gas and dust in both protoplanetary and young debris disks (the Open Time key project GASPS). One of the aims was to investigate the evolution from gas-rich planet-forming disk to the final debris disk and planetary system. As well as being part of the team reducing and analysing these data, you will be using ground-based facilities to follow up some of these results. In particular, this will include ALMA 'Early Science' projects to make resolved images of the gas and dust in such disks. This project will allow the student to get involved with the exciting early phases of ALMA. Additionally this would include complementary observations of the gas and dust with infrared/optical instruments such as CRIRES and SPHERE on the VLT, as well as the extensive use and development of models to explain the data.

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