Potential PhD Topics
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The following list outlines particular PhD projects currently on offer. Contact the staff member(s) listed for more information. Note that, due to the nature of research, this list constantly changes; potential PhD candidates are encouraged to contact the relevant staff member(s) as soon as possible. IMPORTANT: Other projects, not listed here, may be possible; contact the staff member above whom you feel is most suited to your ideas and areas of interest. Also, some staff already supervise several students and so may not list specific projects below; they may, however, still be willing to supervise you if they are listed above and you contact them to discuss possible projects.
Dr. Darren Croton:
Supercomputer models of the formation and evolution of galaxies
Supermassive active black holes: galaxy killers or innocent bystanders?
Prof. Karl Glazebrook:
First Light
A.Prof. Alister Graham:
Supermassive Black Holes
The Hubble Space Telescope Treasury Survey of the Coma cluster of galaxies
Dr. Jarrod Hurley:
Deciphering Galaxy Formation and Evolution through Globular Clusters
Evolution of Star Clusters
Dr. Sarah Maddison:
From Dust to Planets
Observations of Grain Growth: the first step towards planet formation
Dr. Michael Murphy:
Galaxies revealed by quasar absorption lines
Laser frequency combs: a new standard for astronomical spectra
The baryon and gas budgets for the Universe
Dr. Emma Ryan-Weber:
Connecting star formation and its products in the early Universe
Gas-rich dwarf galaxies
The gas-rich cosmic web
Supervisor: Dr. Emma Ryan-Weber
A major goal of extragalactic astronomy is to understand and identify the end of the `dark ages' when the first stars and galaxies were assembled.
This project involves performing a double blind experiment to measure the level of star formation in galaxies in fields that have been searched for Intergalactic Carbon. The star formation rates will be measured by the strength of Lyman-alpha emission through a narrowband filter. One of the major challenges of observing in the near-IR is discrete atmospheric emission due to OH. This study will take advantage of a fortunate co-incidence. Clean spectral windows exist between the OH lines at 0.8 and 1 microns, corresponding to triply ionized Carbon and Lyman-alpha, respectively, both at redshift 5.7. These observations will disentangle a hotly debated issue on the origin of intergalactic carbon at high redshift: whether the carbon are the direct result of an ionizing, element-rich outflow from nearby galaxies or whether the intergalactic medium could have been enriched by stars from an earlier era, possibly the first to light-up the Universe.
The first set of data for this project has already been taken using the FORS2 instrument on the 8-metre VLT. Thus, the student could get going quickly on this project. Further observations will be required using the Magellan telescopes in Chile.
Supervisor: Dr. Jarrod Hurley
Despite our in situ view of our Milky Way galaxy and our ability to observe its properties in great detail, we remain highly ignorant about its formation and assembly. The primary goal of this project is to take the archaeology of the Milky Way, and indeed galaxies in general, to a completely new level. This will be done by combining the most ancient and hence best fossil records of past galaxy history - globular star clusters - with the predictive power of state-of-the-art numerical simulations. Specifically, the project will combine galactic-scale simulations of star cluster formation with N-body simulations of star cluster evolution to develop the first non-simplistic picture of how a globular cluster system evolves with time and to determine how this impacts our interpretation of observed Galactic and extragalactic globular cluster systems. Results will include detailed predictions of the internal properties of star clusters - to be confronted with the latest observations - and an insight to the complex and dynamic merger processes that affect the galaxies of our Local Group, and beyond, even today. The grand aim of this project is to place the formation and evolution of globular clusters in its proper cosmological context.
Supervisor: Dr. Jarrod Hurley
Here at Swinburne we have a range of N-body codes that model all facets of star cluster evolution. We also have teraflops computing power at our disposal via the Swinburne supercomputer and access to GRAPE and GPU special-purpose machines. This software and hardware combination means we can produce direct and realistic models of star clusters, including the possibility of direct modelling of Galactic globular clusters for the first time. As such this is a very exciting time for the field of star cluster simulation and a variety of associated projects are available. These include: the destruction of open clusters in our Galaxy; the formation of exotic stars via dynamical interactions in star clusters; the morphology of planetary systems in star clusters; stellar nucleosynthesis feedback in star clusters; the effect of dynamical evolution on the appearance of globular clusters; and intermediate-mass black holes in globular clusters. Plus numerous other possibilities - please get in touch if you have an idea not listed here.
Supervisors: Prof. Karl Glazebrook & Dr. Paul Stoddart (Applied Optics)
A key problem in cosmology is finding the epoch in time when the first structures in the Universe collapsed to form the first stars. The UV from these stars ionized the neutral hydrogen in the universe left over from the Big Bang, a process called 'reionization'. Current observations have pushed this epoch back to z > 7.
Accessing this epoch required deep NIR observations because all the emission from candidate objects is redshifted out of the optical region. Such observations are difficult because of the bright airglow from the night sky at these wavelengths. At Swinburne we are developing a new technology photonic filter which if successful could suppress this emission and make existing telescopes 10-20x more sensitive. Another technological advance is the advent of MCAO (Multi-Conjugate Adaptive Optics) which could allow for deep NIR imaging over wide fields with a spatial resolution better than HST.
Part of this PhD project will be to work on the design, development and testing of this filter. The other part will be to carry out deep near-IR observations (possibly using this filter) to detect galaxy poplulations beyond z > 7 using the classical 'Lyman Break technique'.
Supervisor: Dr. Sarah Maddison
With over three hundred newly discovered extra-solar planets, it is becoming very important to study the planet formation process. There is an ongoing project at Swinburne to study the earliest stages of the process in which micron size dust particles aggregate together to form metre size boulders that form the base material for planets. The PhD student will work on the theoretical aspects of the problem, using and modifying our 3D, dust+gas hydrodynamics code, and run simulations on the Swinburne supercomputer. Sarah is currently collaborating with groups in France on this project and the new student will become involved with these collaborations.
Supervisor: Dr. Michael Murphy
As the light from distant quasars travels through the Universe on its way to Earth, it occasionally passes through the outskirts of a galaxy. By identifying the absorption lines in quasar spectra that they cause, we can detect galaxies which may otherwise be too distant and faint to see with direct imaging. This is a potentially huge advantage of so-called "absorption selection". But there's a catch: the link between the absorption line properties and the galaxy properties is still unclear and so we must first study a sample of absorption-selected galaxies which are not so faint and distant as to be directly imaged to establish this relationship. Unfortunately, it's difficult to see even bright galaxies in the glare of the background quasars and most attempts at this have failed. However, with the Very Large Telescope in Chile (VLT) we have recently studied some details of some special classes of absorption-selected galaxies. We now aim to obtain Hubble Space Telescope observations to further characterise these galaxies. Large, ground-based telescopes like the VLT and Keck (Hawaii) will also be used to find more distant, and possibly more representative, galaxies. This project is observational in nature. There is opportunity for collaboration with groups based in Cambridge (UK), California (USA) and Victoria (Canada).
Supervisor: Dr. Emma Ryan-Weber
The discovery of the lowest luminosity gas-rich dwarf galaxy, Leo T has sparked a renewed interest in gas-dominated satellites of the Milky Way and Local Group of galaxies. The number of dark matter haloes in the Local Group predicted by cosmological simulations is typically of the order of hundreds - far more than the number detected to-date. Only those dark haloes that can maintain sufficient cool gas, allowing star formation to proceed, produce dwarf galaxies. This project will address the issue of the how many gas-rich dwarf galaxies exist in orbit around the Milky Way.
The student will develop new algorithms to search neutral hydrogen data for gas-rich dwarf galaxies, starting with existing data from the Galactic All Sky Survey conducted with the Parkes Telescope. The final aim is to use data from ASKAP - the Australian Square Kilometre Array Pathfinder, a next generation radio telescope, to be located in a unique radio-quiet zone in Western Australia, which will commence science operations and surveys in 2012. ASKAP will increase the sensitivity in the search for gas-rich local group dwarf galaxies by a factor of 100.
Supervisor: Dr. Michael Murphy
The 2005 Nobel Prize in Physics was awarded for the invention and application of the new laser frequency comb (LFC) technology. As the name suggests, LFCs provide a series of equally spaced "emission lines" which cover a very broad range of wavelengths. I am working with the European Southern Observatory (ESO) on building a LFC system that might be used to provide an ultra-precise wavelength standard for spectrographs on the Very Large Telescope in Chile and even on the planned European Extremely Large Telescope. But to understand how precisely we can really calibrate a spectrograph, sophisticated models must be constructed which allow us to simulate LFC spectra and how they are recorded with digital detectors like CCDs.
This project mainly involves computational modelling and data analysis but it may also involve testing a LFC at the Anglo Australian Telescope in collaboration with the Centre for Atom Optics and Ultrafast Spectroscopy at Swinburne. The student would also collaborate with ESO to produce computer models of their planned LFC system, an effort which has just begun in Trieste (Italy).
Supervisor: Dr. Sarah Maddison
With over three hundred newly discovered extra-solar planets, it is becoming very important to study the planet formation process. There is an ongoing project at Swinburne to study the earliest stages of the process in which micron size dust particles aggregate together to form metre size boulders that form the base material for planets. The PhD student will work on the observational aspects of the problem. Using the Australia Telescope Compact Array, the student will conduct millimetre and centimetre surveys of southern star forming regions to determine grain growth signatures in protoplanetary disks. This survey will be complimented by infrared studies to determine correlations between grain growth in different regions of the disk. Sarah is currently collaborating with groups in the Netherlands and the USA on this project and the new student will become involved with these collaborations.
Supervisor: Dr. Darren Croton
Using state-of-the art simulation and modelling techniques we will build entire universes from the ground up. This will begin with the evolution of dark matter and dark energy through N-body simulations of the evolving cosmic web, and be coupled with the phenomenology and physics of galaxy formation using analytic and semi-analytic methodologies.
The project has two primary aims: 1) We will develop a new model of galaxy formation that better reproduces the multi-wavelength properties of galaxies across ~10 billion years of evolution. This model will be compared with observations from the radio to optical to x-ray wavelengths. 2) We will construct mock catalogues and lightcones from the model galaxies/dark matter halos and use these to interpret the results from modern large-scale galaxy surveys (e.g. 2dFGRS and SDSS locally, DEEP2 and WiggleZ at z~1). We will also make predictions for upcoming "next generation" surveys, such as the Dark Energy Survey (DES), and data taken with the Large Synoptic Space Telescope (LSST) and Square Kilometre Array (SKA), amongst others.
I anticipate a number of published papers will result from this project, as well as the potential for collaboration with teams in Australia, Europe and the US. The student will be encouraged to present his/her results at at least one national/international conference each year.
Supervisor: Dr. Darren Croton
Active galactic nuclei (AGN) represent a unique population of objects in the Universe that encapsulate many otherwise diverse areas of physics. These include extreme environments of gravity (black holes), sub-to-kiloparsec-scale dynamics (black hole two and three body interactions and host galaxy mergers or secular triggers of black hole activity), sub-to-kiloparsec-scale hydrodynamics (gas infall, accretion disks, and AGN winds or jets), and their use as cosmological probes of the evolving large-scale cosmic web.
Black hole and galaxy growth are clearly linked, and there is a need to understand their common phenomenology in greater detail. This project will use the Swinburne supercomputer to develop detailed semi-analytic models of black hole formation and AGN activity to study their impact on galaxy evolution. In particular, there is strong evidence that AGN are the cause of the observed death of massive galaxies. How and when does this happen? What are the possible triggers, and are there unique observational signatures to discern one from the other. What multi-wavelength observations can be leveraged? Does black hole formation regulate bulge formation, or vice versa?
I anticipate a number of published papers will result from this project, as well as the potential for collaboration with researchers in Europe and the US. The student will be encouraged to present his/her results at at least one national/international conference each year. This project can be linked with parts of the previous project, "Supercomputer models of the formation and evolution of galaxies", as the students interests lead them.
Supervisor: A.Prof. Alister Graham
It has recently been recognised that "supermassive black holes", with masses one million to one billion times more massive than our Sun, reside at the heart of most galaxies (even those without an `active galactic nucleus'). Curiously, they appear to consistently represent 0.2 percent of the host galaxy's mass. Better understanding the connection between a galaxy's global stellar distribution and its central stellar density is expected to yield valuable insights into this phenomenon. This can be achieved through the careful analysis of Hubble Space Telescope images at optical and near-infrared wavelengths. Moreover, such high-resolution images actually allow one to measure the galactic damage caused by these cosmic wrecking balls. This will be achieved by carefully studying the images of some 50 galaxies with already measured supermassive black hole masses.
Supervisor: Dr. Michael Murphy
As the Universe evolves, gas is turned into stars and then, when the stars explode, the baryons are liberated into gas again. But through this recycling of interstellar material, we expect that the amount of neutral hydrogen available for star-formation should decrease as the Universe evolves. Tracking this depletion of neutral gas is one of the fundamental observational pointers for theories of galaxy formation. Most of the neutral gas in the early Universe resided in so-called "damped Lyman-alpha" systems (DLAs) -- gas clouds identified in quasar spectra by their strong (damped) neutral hydrogen Lyman-alpha absorption line. But now most gas resides in stars and, assuming that DLAs really do trace the formation of stars, it is hypothesised that the number and hydrogen content of DLAs should therefore have decreased over the past 5 billion years. This PhD project aims to find evidence of this: if it's found then it will help constrain theories of galaxy formation; if it isn't found then it will profoundly impact our understanding of the link between DLAs and star formation throughout the Universe. This is an observational project: we have begun an extensive survey for DLAs aimed at finding evidence for evolution in the DLA population. Observing time on the Shane 3-m telescope at Lick Observatory (California) is already secured and we are seeking time on larger telescopes like the 4-m William Herschel Telescope (La Palma, Spain), the Multiple Mirror Telescope (Arizona) and 10-m Keck Telescope (Hawaii). This is part of a collaboration with researchers in the UK and USA.
Supervisors: Dr. Emma Ryan-Weber & Dr. Rob Crain
The Australian Square Kilometre Array Pathfinder ASKAP is a next generation radio telescope incorporating novel receiver technologies and state-of-the-art data management systems, to be located in a unique radio-quiet zone in Western Australia. The $100M telescope will commence science operations and surveys in 2012, and is a precursor to the full Square Kilometre Array (SKA). The hemisphere and deep surveys for neutral hydrogen emission are expected to detect 600 000 and 100 000 galaxies, respectively. This large data-set will allow statistically meaningful comparison with neutral hydrogen detected in absorption in the intergalactic medium (IGM). The 'Cold Dark Matter' model of galaxy formation has been highly successful at describing large scale distribution of normal galaxies. This project will broaden the application of this model to the IGM where the model has not been tested before. The student will develop new techniques which will be tested on simulated galaxy and IGM data using the Swinburne supercomputer. This new methodology will be used to give a full 3-D tomographic view of the matter distribution, which will provide insight into how galaxies acquire gas. The techniques will be applied to ASKAP data when its comes on-line.
Supervisor: A.Prof. Alister Graham
The HST survey of the Coma galaxy cluster (http://astronomy.swin.edu.au/coma) is one of only two prestigious Cycle 15 (2006/7) Treasury Programs. It involves more than 40 research astronomers from eleven nations. It is the first survey of a nearby rich cluster using Hubble's Advanced Camera for Surveys. While the core of the Coma cluster is the densest galaxy environment in the local universe, the cluster as a whole harbors regions of widely varying galaxy densities. As such it allows one to study "environmental" influences on the physical properties of galaxies. There is opportunity for a PhD research project to study the central structure of these galaxies, where nuclear star clusters and black holes reside.