Potential PhD Topics
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.
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. 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.
Prof. Matthew Bailes
A.Prof Chris Blake
- No projects offered at this time
Dr. Jeff Cooke
Prof. Darren Croton
A.Prof. Chris Fluke
Prof. Duncan Forbes
Prof. Karl Glazebrook
- The fundamental physics behind galaxy formation
- Playing Einstein’s Unfinished Symphony
- Monster galaxies in the early Universe
Prof. Alister Graham
Prof. Jarrod Hurley
- A new paradigm of globular cluster formation with multiple stellar populations
- High Precision Pulsar Timing
Dr. Glenn Kacprzak
A.Prof. Virginia Kilborn
Dr. Glen Mackie
- No projects offered at this time
Prof. Sarah Maddison
Prof. Jeremy Mould
- No projects offered at this time
Prof. Michael Murphy
A. Prof. Emma Ryan-Weber
Dr. Willem van Straten
Specific scholarships are available for these projects.
Professor Matthew Bailes has been awarded a prestigious Australian Laureate Fellowship to discover Fast Radio Bursts (FRBs), millisecond pulsars (MSPs), and other flashes of radio emission in our Galaxy. He is also the nominated Australian lead on the "Breakthrough Listen" project, a 100M USD project to discover alien transmissions in our Galaxy using the Parkes radio telescope.
These projects involve a dedicated programme at the 18,000 square metre Molonglo radio telescope, over one year on the Parkes 64m telescope and almost a year on the new South African SKA pathfinder the "MeerKAT". A large team will be recruited for this activity including engineers, scientists and programmers. In the first year up to three projects will be on offer with guaranteed scholarships and travel support.
Laureate Project 1 (Engineering) will seek an engineer to optimise the performance of the Molonglo and Parkes 64m telescopes for Fast Radio Burst and Pulsar discovery, timing and the detection of alien signals.This will involve developed advanced filtering techniques for removing radio, working with the Berkeley Wireless Research Lab on Breakthrough Listen, and understanding the limits to our sensitivity using advanced signal processing techniques. Supervisors: Bailes, Flynn and Werthimer (Berkeley)
Laureate Project 2 (Machine Learning) seeks a student to use machine learning techniques to perform pulsar and fast radio burst candidate analysis to search for pulsars and fast radio bursts in real time during the Breakthrough Listen, Molonglo, MeerKAT and Parkes surveys. The student will follow up their discoveries in the optical, IR, radio and X-ray both on the ground and in space, via extant arrangements with world leading facilities (Keck, Magellan, SkyMapper, Zadko, Swift, VLT, GMRT, MWA). A background in physics or astrophysics would be advantageous but students should have demonstrated high capability in computer programming (such as neural networks, c, c++, CUDA, php, SQL, xml and/or python). Supervisors: Bailes, Flynn, Fluke and Werthimer (Berkeley).
Laureate Project 3 (Breakthrough Listen Commensal Science). This project will explore how the time for normal science at the Parkes telescope and the scheduled Breakthrough Listen project can make simultaneous use of the telescope signal to perform pulsar and FRB astrophysics as well as SETI (Search for Extraterrestrial Intelligence), with the aim of greatly increasing the efficiency of both projects. The project does not involve SETI per se, but will concentrate on pulsar timing and searching capability within the sensitivity and field of view improvements SETI operations will bring Supervisors: Bailes, Flynn, van Straten and Werthimer (Berkeley).
New advanced telescopes will monitor 100s if not 1000s of radio pulsars at very high cadence. These high precision observations produce a treasure trove of data that helps define the pulsar population. Astronomers are struggling to cope with the information and this project will teach the student how to conduct very high precision pulsar timing and then have them explore what this teaches us about pulsar origin and evolution. The student will explore population trends and compare them with simulations of binaries performed on the Swinburne supercomputer.
A specific scholarship is available for this project.
Everything we see in the Universe, from galaxies to planets, started their lives as cosmic gas. At very early times the hydrogen in this gas underwent an important transformation, called Reionization, triggered by the birth of the first stars. Understanding this transformation is a key outstanding question in modern astrophysics and sets up the conditions for all that follows. This project will combine innovative supercomputer simulations of cosmic gas and galaxies, with Keck telescope observations of real diffuse gas and galaxies up to 12 billion light years distant. With these we will build our own virtual universes containing hundreds of millions of galaxies, “observe” them using virtual telescopes inside the supercomputer, and compare to observations that distinguish between popular reionization and galaxy formation scenarios. The student will be working with a team of theorists and observers as part of the Australian Research Council-funded Reionization And Diffuse Cosmic Gas project. The PhD project can be focused either theoretically (running supercomputer simulations), observationally (going to the telescope), or towards the newly expanding field of data visualisation and eScience (developing online virtual observatory tools). Or a combination of the above, as the student’s interests dictate.
Present and future synoptic all-sky surveys are set to increase the number of known gravitationally lensed quasars from ~100 to a few thousand. This will improve our understanding of quasar accretion discs and supermassive black holes through the effect of gravitational microlensing. GERLUMPH (the GPU-Enabled, High-Resolution, cosmological MicroLensing parameter survey) aims at improving our theoretical understanding and tools for studying microlensing. In this project, you will 1) investigate and develop data mining techniques to identify and characterize microlensing candidates automatically from synoptic sky surveys using a sample of 2.5 billion simulated light curves; and 2) create improved theoretical predictions for the occurrence of quasar microlensing by combining GERLUMPH with the Theoretical Astrophysical Observatory (TAO) .
Supervisor: Prof. Duncan Forbes
A wide-field image of NGC 1407 and NGC 1400 in the
Eridanus group taken with the Subaru 8m telescope. The
image shows a large number of globular clusters in the
halo of NGC 1407.
The assembly history of the most numerous galaxies in the Universe - ellipticals - is still a mystery despite significant observational and theoretical progress. Current ideas focus on two phases of growth from the inside-out. This PhD will take a unique approach of combining data on elliptical galaxies and their systems of globular clusters using the Subaru and Keck telescopes in Hawaii. Globular clusters are the equivalent of astronomical fossils which formed early in the Universe and are robust to the complex, and sometimes violent processes, of galaxy assembly and growth. With this two-pronged approach the project will determine the likely assembly paths of individual galaxies in the local Universe. The project involves collaborators in California and Europe. The skills obtained are readily transferrable to postdoc positions worldwide. Some past papers can be found here.
Supervisors: Prof. Karl Glazebrook & Danail Obreschkow (ICRAR/UWA) & Roberto Abraham (Toronto)
One of the oldest and most fundamental observations about galaxies is they spin. Rotation drives the majestic spiral structures but also the properties of elliptical galaxies. Surprisingly the angular momentum distribution of galaxies has never been mapped systematically, unlike their mass and size, and neither is it consistently incorporated in to models. However simple physical arguments (Obreschkow & Glazebrook 2014) really do strongly imply angular momentum is critical to understanding the large scale diversity of galaxy structure and the Australian SAMI survey is leading the world to gather the first large scale survey of galaxy spin. The aim of this PhD is to take and analyse SAMI data as well as targeted follow-up data from the Keck telescopes and other high-redshift samples to carry out the first complete census of how angular momentum drives galaxy formation. Data will be compared with new theoretical models being constructed incorporating these new physical ideas as an underlying basis. This PhD offers the opportunity to have a major impact on our basic understanding of galaxies.
Supervisors: Prof. Karl Glazebrook
Strongly lensed galaxies from the Sloan Lens ACS survey team. The red central objects are the massive low-redshift elliptical galaxy causing the lensing, the blue rings and arcs are the lensed background high-redshift galaxies.
Strong gravitational lenses are a ‘rosetta stone’ for cosmology and galaxy evolution as they allow direct measurements of dark matter content, strongly magnified (and amplified) views of high-redshift galaxy-formation astrophysics and fundamental constraints on cosmological parameters. The ‘Big Data' challenge is finding these rare objects in the new generation of large imaging surveys such as the Dark Energy Survey, the LSST data and SKA, which can expand samples from hundreds to tens of thousands of sources. The goal of this thesis is to develop machine-learning based pattern recognition techniques to find these sources automatically (in collaboration with the DES STRIDES team), and follow up the first discoveries on Keck to unlock their science.
Supervisors: Prof. Karl Glazebrook
Monster baby galaxies - an unexpected and puzzling find! The right (serious) panel shows two ~1011 solar mass z~4 early type galaxies found by the ZFOURGE survey in ultra-deep K-band data. These galaxies are also ultra-compact (effective radius < 1 kpc) and appear to be quiescent suggesting they have not formed stars for at least 500 Myr. (For comparison the Milky Way evolved back to these redshifts would be >> 100x less massive and undetectable.)
A new puzzle at the distant frontier of galaxy evolution is the discovery of massive galaxies as early at z>4 (<2 Gyr after the Big Bang) containing as much as 1011 solar masses in stars. While such massive galaxies are common today, forming so many stars so soon in single objects may present a challenge to Lambda CDM cosmology, and has been called ‘The Impossible Early Galaxy Problem.’ Our group has performed one of the world’s deepest K-band surveys (the ZFOURGE imaging survey) and has been instrumental in finding these objects (Straatman et al. 2014). In addition to the large stellar masses a significant number are compact early type galaxies indicating that they stopped forming stars even earlier! The goal of this PhD is to trace the detailed properties of these objects in the ZFOURGE survey, and to take spectra with Keck of some of these objects to confirm their nature.
Supervisor: Prof. Alister Graham
Ultraviolet image of the Andromeda Galaxy taken
with NASA's Galaxy Evolution Explorer.
Image credit: NASA/JPL-Caltech
This project will explore how stars are distributed in galaxy images obtained from both ground-based telescopes and satellites such as Hubble and Spitzer. The structure of galaxies reveals much about how they formed, how they are connected with one another and also with the massive black holes that reside in their cores. A feeling for the type of research done with Prof. Graham can be seen in his Press Releases.
One specific PhD project on offer will involve a search for the descendants of the massive, compact galaxies known to exist in the high-redshift, i.e. young, Universe but reportedly now missing today. Another project will, quite literally, measure the observed damage caused by massive black holes at the centres of giant galaxies.
Supervisor: Prof. Jarrod Hurley & Kenji Bekki (UWA)
Snaphot of a star cluster simulation performed with NBODY6, where stellar and evolution and stellar dynamics have combined to produce a population of exotic stars and binaries.
Galaxies consist of stars, gas, dust, and dark matter, with the vast majority of stars formed as star clusters. As such, star clusters are fundamental building blocks of galaxies, containing valuable information on the chemical evolution, star formation histories, and stellar dynamics of galaxies. Recent observational studies of the Galactic globular clusters (GCs), which are the most massive and oldest class of star cluster populations, have discovered that most of the GCs consist of different stellar populations with different chemical abundances – GCs are no longer a simple stellar system with a single age and a single metallicity, as previously thought. This new discovery has revolutionized the research field and this timely PhD project will take full advantage by:
- constructing a new theoretical model for the formation and dynamical evolution of GCs with multiple populations;
- using this model to understand and explain the latest observations of GCs (such as chemical abundances, stellar kinematics and radial structure).
Supervisor: Dr. Glenn Kacprzak
Cool gas (blue) from cosmic filaments accretes onto
the galaxy, which drives its rotation and controls
the rate at which it forms stars. Star formation and
supernovae expel gas back into the circumgalatic medium (purple). Background quasars are used to study
these gas flows around galaxies.
Ever wonder why some galaxies form stars while others do not? Or where does all the fuel for star-formation come from and what regulates it? The evolution of galaxies is intimately tied to their gas cycles - the gas accretion, star formation, stellar death and gas expulsion. As galaxies evolve, their gas cycles (known as feedback), give rise to an extended gaseous halo surrounding galaxies. Understanding how feedback works has become recognized as THE critical unknown process missing to fully understand galaxy evolution. Therefore, galaxy halos are the key astrophysical laboratories harboring the detailed physics of how galactic feedback governs galaxy evolution. The student will have the choice between a theoretically and an observationally based project.
Project 1: Observationally, galaxy halos are studied with great sensitivity using quasar absorption lines. Imprinted on the quasar spectrum are the motions, chemical content, density, and temperature of the gas. These absorption signatures provide details that are onobtainable using any other method of observation. Here, the student will examine how feedback processes effect their host galaxies using using Hubble Space Telescope data and will be involved in the acquisition, reduction, and analysis of data from the Keck telescopes.
Project 2: Disentangling these feedback processes has not been successful using observations of galaxies alone; a complete understanding of galaxy evolution requires detailed simulations of galaxies and their gaseous halos. Using both observations of galaxies and simulated galaxies, the student will aim to develop an understanding of "galactic feedback" and its influence on galaxy evolution. The student will become part of an international team that will examine the properties of gaseous halos and feedback processes with state-of-the-art simulations.
Supervisor: A.Prof. Virginia Kilborn & Prof. Gerhardt Meurer (University of Western Australia)
We are becoming increasingly aware that the galaxy group environment plays an important role in the evolution of galaxies. Galaxy groups are the most common environment in the Universe (over 50% of galaxies live in groups), and the proximity of galaxies in groups, and their low velocity dispersions provide conditions conducive to galaxy interactions. Many of the properties of clusters (e.g. high early-type fractions, redder stellar populations) are often observed in the group environment. This project will take a detailed look at the star forming properties of galaxies in nearby groups, using observations of their neutral hydrogen content, and current star formation rates. The neutral hydrogen (HI) observations are taken from the HI Parkes All Sky Survey (HIPASS) with high-resolution follow-up observations from the Australia Telescope Compact Array (ATCA). The star-forming properties of the galaxies will come from the Survey of Ionization in Neutral Gas Galaxies (SINGG).
The SINGG survey was an H-alpha follow-up program, examining the star forming properties of HIPASS galaxies. Around 400 galaxies were observed in the Survey. Most of the galaxies observed were found to correspond with individual star forming galaxies - however, in about 5% of the cases there are four or more H-alpha emitting galaxies at the position of the HIPASS source. The HIPASS observations have very poor resolution so we do not know the HI content of the individual SINGG galaxies. To overcome this problem, we have performed high-resolution HI imaging with the ATCA - these data will allow us to distinguish the HI content of the individual galaxies. Since HI typically exists in a disk extending out beyond the optically bright portion of galaxies, it often shows signs of tidal disturbance and interaction. This the HI in these fields may give a better indication of how the galaxies in these groups are interacting. The student will assist in the observations, data reduction and analysis of the HI data. It is envisioned that the PhD student will lead this project and extend the data to other wavelength domains. This project will be co-supervised by Prof. Gerhardt Meurer (University of Western Australia).
Supervisor: A.Prof. Virginia Kilborn
Detailed, resolved, HI images exist for less than one thousand galaxies. Making such images is time consuming, and requires use of radio telescope interferometers such as the Very Large Array (VLA), Australia Telescope Compact Array (ATCA), Giant Metrewave Radio Telescope (GMRT), and the Westerbork Synthesis Radio Telescope (WRST). Galaxies have been mapped in HI for a number of reasons – for example, spiral galaxies in the Virgo cluster have been mapped for HI to understand environmental effects in dense regions (e.g. Chung et al. 2009, AJ, 138, 1741). The Local Volume HI Survey (LVHIS, Koribalski et al. in prep) mapped all the nearby galaxies that had been detected in HI from HIPASS (approx 65 galaxies), and the Westerbork HI Survey of Irregular and Spiral Galaxies (WHISP, van der Hulst et al. 2002) mapped a few hundred spiral and irregular galaxies. The “THINGS” (Walter 2008, AJ, 136, 2563) and “Little THINGS” (Ashley et al. 2013, AJ, 146, 42) surveys mapped a few tens of galaxies to high sensitivity in multi-wavelength bands. In addition to these coordinated surveys, individual galaxies have been mapped for various reasons (usually due to interest in particular galaxy or region) – data from all the above telescopes becomes accessible to the public typically 12-18 months after the observations – thus a treasure trove of data is available in the online archives.
The advent of the next generation radio telescopes, in particular the SKA pathfinders ASKAP and Apertif will change this paradigm, with resolved images expected for more than 10,000 galaxies with ASKAP alone as part of the WALLABY all-sky HI survey.
This PhD project will use archive data as detailed above, along with dedicated observations to investigate the relationship between the HI properties of galaxies and their optical properties. In particular the student will investigate the HI extent, profile, and HI surface density of galaxies of differing optical properties (such as morphology and colour) as a function of stellar mass.
The student will be co-supervised at the ATNF, and will be expected to spend time working on the ASKAP BETA array initially – both making observations, and reducing and analyzing early science results. The student will be involved with ASKAP-12 and WALLABY early science, in particular the investigation of HI in different environments. There is a natural synergy with this project, and the SkyMapper survey.
Supervisor: Prof. Sarah Maddison
7 mm image of the Fomalhaut debris disk made with ATCA.
The disk centre (blue star) is offset from the central
(yellow) star, in agreement with HST observations,
possibility due to the eccentric planet Fomalhaut b. From Ricci et al. (2012).
Planets are formed through the collisions of asteroid-like bodies in the early stages of planetary systems. But collisions between these bodies can also be disruptive and generate a swarm of dust fragments. The dust in debris disks is thought to be produced by collisions between km-sized planetesimals (comets and asteroids) leftovers of the planetary formation process. Since we cannot detect planetesimals, sub-mm and mm wavelength observations of the cold dust in debris disk is the only way to study these unseen bodies. Thermal dust emission in the sub-mm and mm wavebands can be used to study the size distribution of dust grains, which in turn can be used to distinguish between different collisional models. In this project, the student will join an international term conducting a survey of debris disks called PLATYPUS with the Australia Telescope Compact Array to study their intrinsic properties and test predictions of collisional models of planetesimals.
Animation of the reionization of helium gas in the
Universe: As the UV light from powerful quasars ionizes
helium in the intergalactic medium, the gas heats up.
But when all the helium is ionized, the quasar light
can no longer heat the gas; it passes straight through and
the gas begins to cool down as the Universe expands
As the Universe expanded and cooled after the Big Bang, the first stars and galaxies formed from “pristine gas” – predominantly hydrogen and helium left over from the Universe’s first few minutes. When those first stars exploded as supernovae, they dispersed the heavy metals synthesised during their short lives and spectacular deaths into the intergalactic medium. These first stars probably also "reionised" much of the Universe’s hydrogen gas with their ultraviolet light, leaving neutral gas only in large, diffuse, enriched filaments laced with proto-galaxies. Thus, after just 1 billion of its current 14 billion year history, the gas surrounding early galaxies likely comprised metal-enriched filaments and outflowing gas, and perhaps vestiges of the pristine gas, relics orphaned from the nurseries of the first stars.
This project aims to verify and quantify this picture of early galaxies, their surroundings, and the intergalactic medium. Several different research directions are possible, though most will involve using quasars as bright, background light sources to probe and understand the gas seen in absorption. Some example topics include:
- Identifying extremely metal-poor and possibly pristine gas pockets in the early Universe;
- Weighing the universe by searching for new examples of deuterium absorption;
- Tracking the evolution of the intergalactic medium's thermal state; and
- Studying how galaxies are fueled by new gas from their surroundings.
Opportunities exist for collaboration with researchers in California (USA), Cambridge (UK) and Heidelberg (Germany), depending on the topic. It is envisaged that this project will be observational in nature, but students interested in the theoretical and simulation aspects of these topics are also encouraged to apply.
The details surrounding the end of the Epoch of Reionization is one the most topical questions in modern astrophysics. Less than 1 billion years after the Big Bang, the hydrogen gas in the Universe encountered a fundamental phase change and transitioned from a neutral to ionized state. The most likely source of the ionizing radiation behind this change is Lyman-continuum emission escaping from galaxies. The problem is that we only have a fragmented understanding of what types of galaxies provide the most ionizing flux at any point in the history of the Universe. Galaxies at redshifts of 3 to 4 are in a ‘sweet spot’ for detecting their Lyman-continuum radiation and can inform us of the contribution by galaxies at earlier times. The aim of this PhD project is to measure the escaping flux from galaxies at redshifts of 3 to 4 and to characterise their properties (such as luminosities, morphologies, and emission lines) for the first time. The project will involve examining existing data from the Keck telescope multi-object spectrographs LRIS, DEIMOS and MOSFIRE, which enable us to collect data for 40 to 100 galaxies at a time. The student will have the opportunity to design and participate in future observing proposals. The project results provide a major step forward in our understanding of galaxies and their impact on their environments and will be applied to the earliest galaxies in the Universe to discover the sources that caused the Epoch of Reionization.