- Gemini Office
Phd and Honours - Honours projects
PhD projects are programs which target significant new bodies of research over a 3-4 year timescale. As an astronomy PhD student you will be involved in developing (with your supervisors) a program of research designed to attack some set of key questions. You will have to write observing proposals, take data, analyse it and prepare it for publication, as well as writing up your results in thesis form. The AAO can offer co-supervision of students in PhD projects together with a University-based supervisor at your home institution.
The following are a few potential projects for PhD students. Astronomy is a subject in which developments move rapidly - so the hot topics by the time a project starts could have changed. All projects are worked out by discussion between you and your prospective supervisor, so treat this list as a source of ideas and a starting point. Members of staff may have other projects waiting in the wings. Students who are interested in subject areas not covered below are encouraged to contact relevant AAO astronomers directly. Students who are interested in projects in astronomical instrumentation should contact Andrew Sheinis, the AAO's Head of Instrumentation.
Project: The angular momentum of massive galaxies
Supervisor: Sarah Brough
Our current model of the formation of galaxies suggests that they grow gradually over time through mergers with other galaxies. The most massive galaxies observed today have therefore gone through many such mergers. The initial galaxies are thought to start off as rotating systems and with each merger the galaxy loses more and more rotation until they are barely rotating at all. However, small studies of some of the most massive galaxies, Brightest Cluster Galaxies (BCGs), find that some are still rotating, in stark contradiction to our current picture.
Until recently, there were only small numbers of observations of these massive galaxies. The ground-breaking multi-object integral-field SAMI galaxy survey now means that there are observations of hundreds of these galaxies. This project will therefore use SAMI observations to resolve this conundrum and understand why some massive galaxies are still
rotating. Integral field observations are the future of astronomy so this project will be an important grounding in a crucial new technique.
Project: The unbound stars of massive galaxies
Supervisor: Sarah Brough
One of the pressing, unanswered questions in astronomy is why the most massive galaxies in the Universe are not observed to have grown in mass as much as theoretical models suggest that they should have. A possible solution is that galaxies merging with the most massive galaxies may actually be destroyed into clouds of unbound stars in the process. This would also explain the origin of diffuse, stellar haloes observed around some of the most massive galaxies: Brightest Cluster Galaxies (BCGs). BCGs are massive elliptical galaxies found at the centres of groups and
clusters of galaxies.
This project would utilise data from the multi-wavelength imaging and spectroscopic Galaxy And Mass Assembly (GAMA) survey to select the BCGs and undertake initial surface brightness analyses before obtaining new deeper imaging from world-class international telescopes to measure the mass of diffuse light and its origin for the first time. This project will provide key skills in data mining, image analysis and obtaining astronomical observations.
Project: Supernovae and Star Formation in Luminous Infrared Galaxies
Supervisor: Stuart Ryder
Stars bigger than 8 times the mass of our Sun are doomed to end their lives in colossal explosions we experience as "supernovae". Measuring the rate at which stars explode today is the key to unlocking the star formation history of our Universe, on which so much of cosmology rests. Despite the dedicated efforts of amateur astronomers and robotic surveys, we know we are missing a substantial fraction of supernovae still.
If you wanted to increase your odds of discovering a supernova, where better to look than the so-called Luminous (or even Ultra-Luminous) Infrared Galaxies ("LIRGs") where short-lived, massive stars are being formed more rapidly than anywhere else in the Universe? The trouble is LIRGs are so dusty that even the largest telescopes can barely see into them at optical wavelengths. By observing at infrared wavelengths, we can see deeper into the LIRGs where supernovae could be hiding. Furthermore, we can use the technique of adaptive optics to overcome the blurring effects of the Earth's atmosphere, and help to reveal the supernovae and the stellar clusters in which they form.
Beginning in 2008 we embarked on a campaign to find supernovae in LIRGs, using the Laser Guide Star adaptive optics system on the 8 metre Gemini North telescope, and have already discovered 2 supernovae. From 2012 we will expand the search to southern hemisphere LIRGs using the Australian-built Gemini South Adaptive Optics Imager. Opportunities exist for a PhD student to play a key role in coordinating this campaign, in image analysis, and following up the supernova discoveries they make at infrared and radio wavelengths. In addition to discovering supernovae, the student will use the resulting LIRG images (the sharpest and deepest ever obtained) to work out what drives the extreme star formation in the first place.
Project: Outer kinematics and chemistry of nearby galaxies
Supervisor: Caroline Foster
The outskirts of galaxies retain signs of galaxy assembly that can last for billions of years and are otherwise invisible in the galaxy centres. Recent literature have shown that several galaxies exhibit interesting and dramatic kinematic transitions beyond the usually probed inner regions. This transition to a kinematically distinct halo (KDH) is predicted theoretically although it has only recently been confirmed observationally. How common this feature is, its possible association with stellar population transitions or as a function of Hubble types remain to be explored using a sizeable samples.
Using world-class optical telescopes in Hawaii and Chile, the "SLUGGS" (near infrared) and "Dragons" (visible) projects are obtaining large scale reconstructed kinematic and chemical abundance maps for a sizeable sample of nearby galaxies. These two surveys are highly complementary, covering different spectral wavelengths and galaxy types, thereby enabling a deeper understanding of systematics.
This project offers the possibility of early involvement in the new Dragons survey, the use of data from world-class observatories and of a recently developed data reduction technique (Norris et al. 2008; Proctor et al. 2009) to push the galactocentric boundary. The selected student will acquire invaluable spectral and kinematical analysis skills that are easily portable to popular IFU studies. The Dragons survey is an international collaboration between scientists in Australia, Canada, Chile, USA and The Netherlands, hereby offering a connection to further worldwide opportunities.