Potential PhD Topics
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(Updated 20/08/2009)
Below are listed those CAS staff who are currently looking for PhD students. Note that this does not mean they will always have specific projects listed in the next section of this page. Often it's best to talk to the supervisor first and, upon discussing your interests and skills with them, a project may emerge.
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(Updated 14/12/2009)
(IMPORTANT: The list of projects below has not yet been updated for our May 2010 PhD application round. This will be done in February 2010.)
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. Chris Blake:
Testing cosmological models with the WiggleZ Survey
Dr. Darren Croton:
Galaxy and black hole co-evolution, 6 to 12 billion years ago
Supercomputer models of the formation and evolution of galaxies
The rate of galaxy assembly in extreme over- and under-dense regions of the large-scale cosmic web
Prof. Duncan Forbes:
Dark matter in elliptical galaxies
Unveiling the dark halos of elliptical galaxies
Prof. Karl Glazebrook:
First Light
A.Prof. Alister Graham:
Compact elliptical galaxies
Dark matter in elliptical galaxies
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. Glen Mackie:
Physical properties of Near Earth Asteroids
Testing Galaxy Formation in the extreme - The Shapley Supercluster
Dr. Michael Murphy:
Do the fundamental constants of Nature vary in spacetime?
Galaxies revealed by quasar absorption lines
Laser frequency combs: a new standard for astronomical spectra
The baryon and gas budgets for the Universe
Supervisor: A.Prof. Alister Graham
Compact elliptical (cE) galaxies are a rare and intriguing class of object. While considered to be the true dwarf analog of ordinary elliptical galaxies by some, others have questioned their very nature, suggesting that they are not even elliptical galaxies but rather two-component systems with perhaps even an outer disc. There is also tentative evidence that cEs may be linked to the bulges of spiral galaxies. This project will analyze all known cE galaxies, in conjunction with images of spiral galaxies, with the goal of settling this long standing debate, possibly redefining an entire species of galaxy.
Supervisor: A.Prof. Alister Graham; Associate Supervisor: Prof. Duncan Forbes
Within the standard cold dark matter model of hierarchical galaxy formation, galaxies form within halos of dark matter. Exactly how much dark matter (if any?) resides within the inner regions of elliptical galaxies is far from universally agreed upon. This project, better suited to those with applied mathematics and basic numerical coding skills, aims to explore this issue and determine the mass-to-light ratios of elliptical galaxies. There may also be the opportunity to acquire and analyze spectroscopic data from dwarf elliptical galaxies taken with the Keck Telescope in Hawaii.
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. Michael Murphy
The constants of Nature play a central role in our fundamental physical theories, but these theories cannot predict the values of the constants we observe. Indeed, this is one hint that our theories may be incomplete and that a more fundamental, "grand unified theory" linking all physical interactions -- gravitational, electromagnetic and nuclear -- might exist. Perhaps surprisingly, the absorption lines seen in the spectra of extremely distant quasars offer a fairly clean and precise probe of the values of some fundamental constants early in the Universe's history. Over the past 10 years, tentative -- and tantalising -- evidence that some constants may actually vary on 10 billion-year time-scales has emerged from quasar studies. This PhD project aims to challenge that evidence with new observations of quasar absorption systems.
Together with international collaborators, we have recently been awarded a "Large Programme" on the European Southern Observatory's 8-meter Very Large Telescope (VLT) in Chile, one of the world's cutting-edge telescopes. The Programme comprises approximately 37 nights of observing time in 2010-through-2012 and will provide the very best quasar absorption spectra dedicated to the "varying constants" question.
Many different avenues may be followed in this project, all of which are mostly observational in nature. For example, the student may tackle the core project -- i.e. analysing the new quasar spectra to measure possible changes in fundamental constants over cosmological time- and distance-scales -- or address other important questions, e.g. what is the ultimate measurement precision in this work? The student will have an opportunity to participate in the new VLT observations and to work with collaborators in Trieste (Italy), Sydney and Brisbane. Some opportunities for gathering supporting data from the Keck telescope in Hawaii are also possible.
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. 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. Darren Croton
Active black holes (AGN) appear to be critical for shaping the properties of many present day galaxies, especially those at the centres of massive clusters. However, the rate of both galaxy and black hole growth is know to be up to an order-of-magnitude higher at z~2 where the environment enabling growth is significantly different. Most models of galaxy formation simply extrapolate known local processes back in time to earlier epochs, but this may not necessarily be a good approximation. Special care needs to be taken to model the physics of such objects in the early Universe, and no model can currently match the level of detail expected from next generation instruments and surveys in this redshift range.
This Ph.D. project will focus on the role of active black holes in galaxy evolution at high redshift. To do this we will extend a current state-of-the-art galaxy formation model to map out different evolutionary scenarios. We will quantify:
- Black hole formation through mergers and disk instabilities
- The AGN light-curve as a function wavelength
- Quasar winds and their effect on galaxy properties
- The galaxy starburst-AGN connection
- The cosmological abundance of different AGN and galaxy types
- AGN and galaxy evolution of z~2 objects to the present day
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. Glen Mackie
Many factors are required to calculate the orbital evolution of Near Earth Asteroids (NEAs) which determine just how hazardous they are to Earth and life. Optical and near-IR photometric, spectroscopic and polarimetric observations can provide constraints on albedo, rotational periods, surface composition, taxonomic classification, size and bulk density. These factors allow the evaluation of potential impact scenarios and the planning of possible mitigation programs. As well they are required in conjunction with radar measurements to more accurately constrain possible orbit evolution. This project will study a number of NEAs to study the above properties and evaluate thermophysical models, leading to better determinations of macroporosity and albedo-size relations.
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: A.Prof. Alister Graham
Supermassive black holes, up to one billion times more massive than our Sun, are known to lurk at the heart of most big galaxies. In contrast, within dwarf elliptical galaxies and the small bulges of spiral galaxies, one typically observes a highly compact star cluster containing some 105-107 stars. However, it has recently been discovered that among the 50+ galaxies with the most reliable black hole mass measurements, a dozen actually have both type of nuclei coexisting. Curiously, their masses scale with each other and also the host galaxy's mass and other physical properties. This project intends to better understand these connections through the careful analysis of Hubble Space Telescope images at optical and near-infrared wavelengths. Such systems are also expected to be fruitful sources (for the LISA satellite) of Einstein's predicted but not-yet-observed gravitational radiation.
Supervisor: Dr. Chris Blake
The large-scale structure of the Universe is one of the most powerful probes of the cosmological model. It allows us to test the nature of dark energy, theories of gravity over cosmic scales, and models of inflation which create the initial conditions. This PhD project would analyze data obtained by the WiggleZ Dark Energy Survey (http://wigglez.swin.edu.au), one of the largest existing galaxy redshift surveys stretching to redshift z=1. The main aim of this PhD project is a careful measurement of the "Fourier modes" which describe the cosmic structure. These can be combined to obtain the "power spectrum" and "bispectrum", with a particular focus on using the bispectrum to determine the cosmic growth of structure. The results will be tested and improved by carefully analyzing simulations of the survey that are being produced using Swinburne's supercomputer.
Supervisor: Dr. Glen Mackie
The Shapley Supercluster (SSC) is the most massive concentration of galaxies in the local universe. Recent redshift surveys have elucidated the distribution of bright galaxies in the core and outskirts of the SSC. The close vicinity of the SSC (cz: 8,000 - 18,000 km/s) and it's large overdensity of galaxies offers a unique perspective into galaxy evolution at the very extreme of space densities. In general star formation appears to be quenched or supressed for recently accreted galaxies. This project would try to answer many remaining questions concerning linkages between star formation rates and cluster environment. Current data includes previous deep optical imaging, HST archival images, previous X-ray imaging and radio continuum studies. Hierarchical models predict clear trends for elliptical galaxies in such environments and we intend to extend current observational vs. theoretical comparisons to below L* galaxies.
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.
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.
Supervisor: Dr. Darren Croton
There are two primary ways a galaxy can grow, either from star formation within the galaxy or from mergers with other galaxies external to it. Recent interest has centred on which of these two growth channels dominate a galaxy's evolution and when. Surprisingly, current galaxy formation theory based on the known LCDM cosmology is in serious conflict with many recent observations of massive galaxy growth in dense environments. Work is needed to understand the relationship between galaxy assembly, environment, and the baryonic processes that can influence them.
This Ph.D. project will study how similar galaxies that reside in different large-scale environments assemble their stellar mass across cosmic time, with particular attention given to z=1-3 objects. We will quantify:
- The different assembly histories of dark matter halos, galaxies and their resident supermassive black holes, including the histories of the pieces themselves and each object¡Çs ultimate fate
- The mass fraction in each galaxy arising from mergers and star formation as a function of galaxy type and redshift
- The environmental differences in galaxy and black hole assembly for galaxies of similar mass
- The cold, warm and hot gas content of the Universe as a function of environment and redshift
- Additional environment dependent physical processes that may alter galaxy evolution
Supervisor: Prof. Duncan Forbes
The halos of elliptical galaxies have been poorly probed to date and yet they contain the vast bulk of the dark matter. Using the world's largest telescope (the Keck 10m located in Hawaii) this project will obtain new dynamical and chemical information for nearby ellipticals. This data will be used to constrain the dark matter content of such galaxies and to better understand their formation processes. The project is likely to involve collaboration with colleagues based in California.