Physics and astronomy research projects
Find information about Physics and Astronomy research project units and details of the projects available.
- Physics Project 1 – Core for all streams, available in both semesters
- Physics Project 2 – Recommended elective for students with a CWA 65 or greater, available in both semesters
- The preferred option is to take PP1 in semester 1 and PP2 in semester 2 and combine them into a single year-long project.
- The choice of project may have a big influence on the direction of your career – so this is an important choice!
- End of semester report (40%)
- Supervisor’s assessment of your performance (40%)
- Oral presentation (PowerPoint or poster) (10%)
- Written summaries of seminars you have attended (10%)
- Fortnightly group meetings with supervisor (0%)
By the end of the second week in December:
- Decide what projects you are interested in and go and talk to potential supervisors.
- Negotiate the details of the project and get an undertaking from the supervisor that they are prepared to take you on.
- Email project coordinator with the title of your project, and the name of your supervisor.
- Please note that students who delay choosing their project to the Orientation week or later cannot be guaranteed that a desired project or supervisor will be available.
The summer scholarships are intended for Curtin’s outstanding recently completed first, second and third year students wishing to undertake research experience aligned with their Physics Stream of interest.
These streams include:
- Applied Physics
- Materials Science
- Theoretical/Mathematical Physics
Examples of projects may be found below. Please contact the potential supervisor to discuss the details.
The scholarship is to be completed over a flexible six week period, upon discussion with the supervisor, before the end of February with a A$3,000 stipend offered.
If you are taking a Curtin Physics Major, as a single or a double degree, and are interested in being considered for one of the Summer Scholarships, apply here.
You are welcome to choose any project from the categories below. Please get in touch with the prospective supervisor, and once agreement has been reached provide the details to the projects coordinator, Irene Suarez-Martinez via I.Suarez-Martinez@curtin.edu.au.
Extragalactic Radio Astronomy
Several Square Kilometre Array (SKA) prototype arrays have been deployed at the Murchison Radio-astronomy Observatory over the last few years. These arrays are intrinsically all-sky instruments, and can image the entire visible radio sky with 1 second time resolution and modest angular resolution. This project will reprocess existing data from the SKA prototype systems to study transient and variable radio sources. Potential sources range from meteors to explosions at cosmological distances.
The Murchison Widefield Array (MWA) has proved itself to be an extremely powerful monitor of the ionosphere. Tiny shifts in the location of radio sources can be detected as they are refracted by the ionosphere and this can be used to detect very large-scale features.
There is also a huge untapped source of data on the much smaller-scales in the ionosphere. In this project you will shed a new light on ionospheric structures just a few hundred metres across by monitoring the location, brightness and shape of very bright radio sources as they shift and scintillate on timescales of order 10s.
At the center of most galaxies is a supermassive black hole; in some galaxies, hot material falling toward the black hole can be launched outward in twin “jets”, moving along the axis of rotation of the black hole at nearly the speed of light. These balloon into enormous radio-bright “lobes” which can be seen billions of light years away. Astronomers are trying to understand what kinds of galaxies do this, how often, and how long activity lasts: the life-cycle of radio galaxies. One challenge is that once the jets switch off, the lobes fade quickly, and without the right observations, we can miss periods of activity. This means that the dying, or “remnant” stage of radio galaxies is very poorly-studied, with only a few examples known, making calculations of the life cycle impossible.
We have selected 40 new candidate remnant radio galaxies and obtained sensitive radio observations using the Very Large Array, a radio telescope in the USA. The student will transform the data into detailed images of the galaxies, and combined with our existing measurements, use our software to model their ages and find out if they are examples of this rare class of objects. If so, this would more than double the number of remnant radio galaxies known, and in combination with the sample from which they were selected, put a new constraint on the activity of supermassive black holes.
Supervisor: Dr John Morgan
Suitability: 3rd year, Honours
Just as stars twinkle in the night sky, radio sources twinkle due to turbulence in the solar wind, a phenomenon known as interplanetary scintillation (IPS). We have developed a revolutionary new way of making IPS observations, detecting many hundreds of sources via their variability (i.e. the standard deviation of a timeseries of brightness measurements). This variability follows an exponential distribution, and we have shown that some of the most compact (and therefore most interesting) IPS sources can also be detected via the skew or kurtosis of the timeseries.
In the project you will use these higher-order moments to detect and characterise the most interesting one or two objects from the many thousands of sources typically detected in an MWA image.
Before the very first galaxies formed, the Universe was a sea of hydrogen and helium, gently cooling and collapsing. When the first galaxies formed, they ionised the surrounding gas, turning it from an opaque absorbing cloud into the transparent, ionised plasma we see today: this time is called the Epoch of Reionisation.
This change will have occurred at different rates in different locations in the Universe. When we look at high-redshift galaxies which emit in the radio spectrum, any neutral hydrogen along the line-of-sight will absorb the characteristic HI line at that redshift. For the highest-redshift galaxies, this HI line is shifted from 1.4GHz down to ~150MHz. This is within the frequency range of the Murchison Widefield Array, a radio telescope operated by Curtin University and based in the Murchison Radio Observatory.
This project aims to detect HI absorption in high-redshift radio galaxies using the MWA. As this is a spectral line experiment, it requires a unique data processing pipeline and careful control of calibration and systematics. Students will apply a pipeline to search for this signal in MWA observations of known high-z radio galaxies. This project is designed to synergise with the project “New high-redshift radio galaxy candidates from GLEAM”.
Supervisor: Dr John Morgan
Suitability: 3rd year, Honours
Just as stars twinkle in the night sky, radio sources twinkle due to turbulence in the solar wind, a phenomenon known as interplanetary scintillation (IPS). As well as being useful for predicting space weather events, IPS can also be used to identify and study extremely compact sources.
We have developed a revolutionary new way of making IPS observations, However we have not yet worked out how to optimally weight or deconvolve IPS images. This is a critical step in making a radio image, and will allow us to make more sensitive observations. This project would suit a student who is interested in doing astronomy with future radio telescopes and would really like to dig down into guts of how radio images are made. It would also suit a student interested in High-performance Computing.
Supervisor: Dr Tim Galvin
Description: The Australian Telescope Compact Array (ATCA) is a six dish radio interferometry located in Narrabri, New South Wales. Since the early 1990’s it has been a cornerstone of radio-astronomy in the Southern hemisphere. In recent years it has performed a series of large observing campaigns, with aims of surveying large fields to new depths and resolutions. For fields of the sky that are larger than the field-of-view of a single observation, a technique called ‘mosaicing’ has to be deployed, which describes the process of stitching together nearby, smaller images into a single larger image. Although this can be a straight-forward process in the simple case of stitching individual images together as a post-processing step, for optimal results this mosaicing needs to be incorporated early into the image processing workflow. DDFacet, an advanced image processor written for the next-generation of radio-telescopes that has only been recently developed, has initially been applied to such ATCA datasets and have demonstrated exceptional improvements over traditional imaging approaches.
This project aims to further investigate this imaging approach, with goals of:
- Creating a initial set of images using DDFacet
- Writing a miniaturized pipeline capable of being deployed on supercomputers
- Verify image and source finding outputs for reliability
The project has multiple datasets that have already been collected and are available for processing including:
- 200 pointings over 250 hours at 6.7 and 9.5 GHz covering the Extended Chandra Deep Field South
- 4000 pointings over 250 hours at 5.5 and 9.0 GHz covering the Small Magellanic Cloud
- 7000 pointings over 3000 hours at 5.5 and 9.0 GHz covering the Galaxy And Mass Assembly 23-hour field.
Although low-frequency (<400 MHz) radio sky is not reported to be highly variable in terms of transient objects, there have been increasing number of transients detections by new low-frequency instruments. Sensitivities of the existing instruments are not high enough to detect all (or at least many) of the low-frequency counterparts of transients detected at higher electromagnetic energies (up to gamma-rays). However, there have been several recently reported low-frequency transient detections. Such as for example detection of the outburst of the black hole candidate X-ray binary MAXI J1348-630 at 154 MHz and 216 MHz with the Murchison Widefield Array (MWA; http://adsabs.harvard.edu/abs/2013PASA…30….7T) by J. Chauhan et al (2019) or detection of a very bright transient (> 800 Jy) of unknown nature by the Long Wavelength Array (Varghese, S. et al (2019)).
This project aims to develop tools for automatic identification of transients in the MWA data.
Over the last two years many observations of calibrator sources were reduced, calibrated and imaged in order to develop a database of calibration solutions for the MWA, specifically for the All-Sky Virtual Observatory (ASVO). Hence, there is a large set of images of the calibrator fields which could be analysed in search for transients as a first and minimal step of the project (3rd year project / Summer Student level). These efforts can be extended towards development of a real or near-real time transient detection system for the upcoming low-frequency component of the Square Kilometre Array (SKA-Low) including all-sky images from the prototype arrays.
Because their emitted light must travel huge distances to reach the Earth, very distant radio galaxies (the so-called high-redshift radio galaxies or HzRGs) are an important window into the Universe’s past: we observe these galaxies how they looked like over 10 billion years ago! In particular, we can gain vital insights into the extreme processes responsible for the growth of their central supermassive black holes (of order a billion solar masses) on short timescales after the Big Bang.
We have developed a new HzRG selection technique using the broadband GLEAM radio survey, conducted with the Murchison Widefield Array (MWA). From a pilot study of four sources, we uncovered the second-most distant radio galaxy currently known, observed when the Universe was less than a tenth of its current age! A second radio galaxy from our pilot might be even more distant, and we are currently analysing Hubble Space Telescope (HST) data to better understand this mysterious source. From a new sample of 55 HzRG candidates, we now aim to detect powerful radio galaxies during the ‘cosmic dawn’ in the very early Universe, which would facilitate a number of exciting, high-impact scientific opportunities!
You will play a leading role reducing, analysing and interpreting the multi-wavelength data for this new sample of HzRG targets that we are currently acquiring from a range of world-class telescopes, including the MWA, the Very Large Telescope (VLT) in Chile, and the Australian Long Baseline Array (LBA). Your analysis of these rich datasets will provide novel insights into the co-evolution of the supermassive black hole and host galaxy during the first billion years of the Universe. How does the central supermassive black hole grow so quickly? How do the powerful radio jets trigger or suppress star formation? Do these black holes play an important role in reionising the Universe?
The Murchison Widefield Array (MWA) is a precursor of low-frequency component of the Square Kilometre Array (SKA_Low) located at the Murchison Radio-astronomy Observatory (MRO) in Western Australia. Its wide field of view (FoV) of the order of 25 x 25 deg^2 makes it a very good instrument for wide field transient monitoring. The goal of the project is to look for variable objects in 2-minutes snapshot data collected by the MWA over all pointing directions above 40 deg elevations. The first dataset was recorded in 2018 and the corresponding dataset at the same local sidereal time will be collected in 2019. Subtraction of the corresponding sky images from the two epochs should enable identification of variable sources, which either appeared, disappeared or changed their flux density between the two epochs.
Supervisors: Dr Natasha Hurley-Walker, Dr Lister Staveley-Smith
Suitability: 3rd-year, Honours, Masters
Our nearest galactic neighbours are the Large and Small Magellanic Clouds, uniquely visible from the Southern hemisphere. These face-on dwarf galaxies offer astronomers a clear view of phenomena such as supernova remnants and regions ionised by massive stars, and inform studies of cosmic ray production and star formation. The MAGE-X project has taken tens of hours of data with the low-frequency radio telescope, the Murchison Widefield Array. This project involves using existing well-developed pipelines to reduce the data on Pawsey supercomputers, producing new high-resolution images of these galaxies. Good progress will enable astrophysical studies in the latter stages of the project. This project would suit a student with strong computing abilities who is interested in working on high-performance supercomputers and/or developing their skills in radio interferometry.
Understanding how and when the first supermassive black holes (SMBHs) formed is a major questions in astronomy. Evidence is mounting that the some SMBHs formed very early in the Universe implying that they had to grow very quickly by accretion of material or mergers form seed black holes formed from the first stars or from collapse of the peaks primordial over-densities of matter. Highly accreting SMBHs shine bright in the optical if they are not obscured. This project aims to search for such sources using the 1000deg^2 VIKING near-infrared survey as well as many radio surveys covering this region.
There are two components to this project. The first is modelling the expected colours of very distant QSOs so that we can select them from the multitude of other sources. The second is run the code to produce the broad band images over this survey. These broad band images are produced by summing several other bands in which the QSO is expected to be very bright or very weak. Then these rare sources should be easily found. In particular we are interested in finding those QSO which are detected in the radio. This project is designed to synergise with the project “ New high-redshift radio galaxy candidates from GLEAM” by finding less radio luminous AGN.
The properties of compact objects (at sub-arcsecond scale) and their population is slowly being understood at low radio frequencies. Our
recent studies suggest that this rare population is comprised of supermassive black holes at centres of massive galaxies and compact
radio galaxies. To understand them better we need sensitive surveys with high angular resolution such that they can be distinguished from the very large population of radio galaxies which can be up to hundreds of times larger in size.
The sensitive GLEAM-X survey has been made with the Murchison Widefield Array (MWA) that will provide exquisite spectral property of radio sources between 70 and 230 MHz, with the angular resolution of approximately 1 arcminute. This is too large to identify the compact source population. Just as twinkling of stars identifies them from the apparently larger planets, the radio analogue of twinkling, called interplanetary scintillation (IPS), can be used to distinguish compact sub-arcsecond scale sources from the larger extended radio galaxies. This technique has recently been implemented on the MWA, and a catalogue of compact objects thus identified from half the possible sky is near complete.
Through this project we aim to combine the strengths of the IPS technique and the sensitive wideband spectral information provided by the GLEAM-X survey to identify different sub-populations of compact sources such as flat-spectrum cores, peaked-spectrum sources and compact steep-spectrum sources. We will obtain a well defined sample from a large area in the sky such that robust studies can be made. We will use this sample to understand the relationship between these sub-populations, and with the entire radio galaxy population. As part of this project you will: learn how radio astronomical data is processed, learn to understand the relationship between angular sizes and spectral properties of different sources and, to classify them into different sub-populations to enable studies of their relationships.
Supervisors: Dr Natasha Hurley-Walker, Dr Ivy Wong
Suitability: Honours, Masters
The growth of central supermassive black holes (also known as Active Galactic Nuclei, AGN) is episodic and not well understood. The Swift BAT AGN Spectroscopic Survey (BASS) is a very large survey (>1000) of hard X-ray selected AGN with complementary optical spectroscopy observations aimed at furthering our understanding of growth and structure around nearby supermassive black holes. A significant recent BASS discovery is the significant excess of late-stage nuclear mergers – a result that is consistent with theoretical simulations which find a strongest excess of nuclear mergers in gas-rich major-merger host galaxies of obscured luminous black holes (Koss et al 2018). The prevalence of mergers suggests that these galaxies do not reside in isolation. High angular resolution is required to pinpoint the origin of the emission.
Current radio continuum studies of this sample have found that while these black holes are accreting very efficiently, at higher radio frequencies they are not radio-silent but typically classed as radio-quiet (Wong et al 2016; Smith et al 2016) and that likely to not be dominated by a jet origin but related to outflow winds (Baek et al 2019; Smith et al 2020 submitted). Low radio frequency observations are currently missing but crucial for tracing past jet episodes and for estimating the mechanical energy that would be injected into the ISM and IGM of the host galaxy. Studying these galaxies with the Murchison Widefield Array will enable the modelling of the radio emission and potentially the age of the jet emission. The GaLactic and Extragalactic All-sky MWA – eXtended (GLEAM-X) survey can be used for this work.
Aims of the project:
i. Examine and characterise the low-frequency radio spectral energy distribution from GLEAM-X observations of a sample of nearby galaxies where AGN activity has restarted (selected via their hard X-ray emission);
ii. (Masters) Estimate contribution of jet emission to observed radio emission across the band.
This project uniquely exploits the frequency coverage of the MWA over 20 bands and the Phase 2 long-baseline observations which provide sufficient resolution for pinpointing the source of the observed low-frequency emission. It allows us to look back into the past of supermassive black holes and examine how they feed and grow. This project suits a student with a strong interest in astrophysics and astronomy.
Modern all-sky radio surveys represent a big data challenge, one where traditional approaches informed by physical expectations may no longer be the most appropriate. The GaLactic and Extragalactic All-sky MWA eXtended (GLEAM-X) project has observed the sky south of Dec +30 across a frequency range of 72 – 230 MHz. When finished it is expected to detect in excess of a million objects across twenty intermediary frequencies. Collectively, these objects and their properties represent a massive multi-dimensional dataset that is difficult to interact with and efficiently mine for meaningful scientific outcomes. This is especially true for rare or previously unseen objects that are buried beneath the more typical sources.
This project will explore how unsupervised clustering methods may best be applied and exploited to create a structured framework to allow objects detected by GLEAM-X to be categorised and explored efficiently. Methods regularly applied in the machine learning community (including auto-encoders, generative adversarial networks, t-SNE etc.) will attempt to organize the contents of the GLEAM-X outputs into a scheme that neatly separates objects into fundamental or regressed classes. These methods are especially powerful as they do not necessarily have to incorporate expectations specified by assumed physical models, thereby avoiding potential bias or constraints inadvertently introduced. When finished, the applied approach would be capable of compressing all object properties into a simple two- or three-dimensional embedding to be made available for exploration. A major outcome of this data-driven approach to modelling is the ability to identify outliers, which in this scenario could be a set of exceptionally rare or previously unseen objects.
Aims of the project:
vii. Develop appropriate clustering methods using existing public catalogues (e.g. GLEAM);
viii. Expand the method to the new GLEAM-X data;
ix. Search for and characterize reference objects such as radio galaxies;
x. Explore outlying populations to discover new populations of sources.
This project is well suited to a student with a good programming background, an interest in developing new computational techniques, and good organisational skills.
Supervisors: Dr Nick Seymour
Suitability: Honours, 3rd year
Near-Earth Objects (NEOs) represent an obvious existential threat to life here on Earth as frequently dramatised in fiction. There are long standing programmes with optical and infrared telescopes around the world and in space to discover and monitor NEOs. The Murchison Widefield Array (MWA) has demonstrated the capability to detect both natural and artificial satellites of Earth such as the Moon and the International Space Station via reflected FM emission. This project will involve determining the feasibility using reflected FM as a ‘static radar’ to monitor and track NEOs with low frequency radio telescopes.
While the MWA will not be as sensitive for detecting NEOs as other programmes currently, future radio facilities, like the Square Kilometre Array, will have many orders of magnitude more sensitivity. In this project you will process MWA observations of the NEO 2012 TC4 which passed around 50,000 km of Earth on Oct 12 2017. As well as direct imaging you will employ other enhanced analysis methods to detect this faint object (which is only about 10m in size). You will also compare the MWA archives to close passes of NEOs over the lifetime of the MWA (and into the near future) to search for other potential observations.
Accretions, Jets and Slow Transients
Several Square Kilometre Array (SKA) prototype arrays have been deployed at the Murchison Radio-astronomy Observatory over the last few years. These arrays are intrinsically all-sky instruments, and can image the entire visible radio sky with 1 second time resolution and modest angular resolution. This project will reprocess existing data from the SKA prototype systems to study transient and variable radio sources. Potential sources range from meteors to explosions at cosmological distances.
Most galaxies host a super-massive black hole at their centre which enters active phases from time to time. The two most significant but different phases of activity are periods of high accretion (which we observe in the X-ray/optical/infra-red) and periods with powerful jets (observed in the radio). These two measurable outputs trace different aspects of the SMBH’s evolution. This project will attempt to link these phenomena both observationally and theoretically to determine a greater understanding of SMBH evolution. It can be tailored for varying levels from summer project to honours.
On the observational side we now have large samples of galaxies from deep/wide surveys with the multi-wavelength data to start untangling accretion and jet processes on a population of galaxies. In particular we now have unique broad-band radio data which can provide more accurate jet powers than have previously been possible. On the theoretical side we will apply simple models of SMBH accretion and jet power to study how an individual SMBH observable properties change with time. This will aid us in interpreting the large observational parameter space.
Suitability: 3rd year (two-semester)/honors
X-ray binaries are systems consisting of a neutron star or a black hole pulling matter from a companion star (that is similar to our sun). As the matter falls towards the neutron star/black hole in an accretion disk, it releases an immense amount of energy in form of X-ray light. As the accretion rate varies stochastically over time, so does the X-ray brightness of the system. Thus this allows us to prob the amount of matter “eaten” by the neutron star/black hole through their variations of brightness.
In this project, we aim to examine the “duty cycle” (frequency of occurrence) of accretion in neutron stars based on archival data and compare them to black holes. We will do this by primarily exploring the past bright “outbursts” (during which the system gets bright and accretion rate exponentially increases) of neutron stars and compare them to black holes.
Some stellar-mass black holes are found in tight binary systems with a companion star. In these systems, the black hole can gradually pull matter from the companion and the pulled material falls towards the black hole in the form of an accretion disk. As the matter falls closer, it releases energy through radiation, allowing us to observe and study various emission signatures of this process. Observations of these signatures have allowed astronomers to establish a rough understanding of the mechanisms through which the infalling matter releases energy. However, there are many details that are still not understood. Many accreting black holes go through “outbursts” in which the system gets orders of magnitude brighter as the amount of matter falling towards the black hole increases. These systems go through multiple states as the brightness and accretion rate varies. In this project, we will focus on a recently discovered accreting black hole as it went through an outburst. This particular outburst is fascinating as after the outburst was over and the system returned to its faint “quiescent” state, it showed numerous unusually bright “after-outbursts” or “mini-outbursts”. So our aim is to characterize the accretion/emission mechanisms in these mini-outbursts.
The Murchison Widefield Array (MWA) is a low frequency (80 — 300 MHz) radio telescope operating in Western Australia and the only SKA_Low precursor telescope. The MWA has collected more than 20PB of data spanning nearly a decade of operations. In an undergraduate project in 2020, using just 24h of data, we detected a new type of repeating radio source, which we have localised to our own Milky Way. The object may be an unusual type of neutron star, or possibly a highly magnetic white dwarf: either way, it was entirely unexpected, and shows the power of searching these archives.
Now that we know such sources exist, it is imperative to find more of them in order to study their nature and their astrophysics. Fortunately, there are thousands of hours of data, representing large volumes of the Galaxy, which have not yet been searched. These data are expected to contain many more examples of this new type of source, as well as other interesting transient events such as M dwarf stars or reflective space junk, which this project aims to discover.
The project uses existing pipelines to search the vast archives of the MWA for interesting transients, with a particular focus on data covering our own Galaxy, where we expect more periodic radio transients to reside. With approximately 7 million source measurements to search and correlate, organisation and clear thinking are crucial skills.
Supervisors: Dr Arash Bahramian
Suitability: 3rd year
47 Tuc is a star cluster containing numerous exotic compact stellar objects like white dwarfs, neutron star or black holes in binary systems with other stars. In these binaries the compact object accretes matter from the companion star in form of an accretion disk. The temperature in the accretion disk can reach millions of degrees, making it emit significantly in the X-rays. X-ray binaries in 47 Tuc are among best study cases among X-ray binaries as their distance is accurately measured and they are not obscured substantially by the interstellar medium. Since the launch of Chandra X-ray observatory, these systems have been studied in details through spectroscopy. However, their timing properties have been left relatively unexplored. In this project, we aim to take advantage of deep continuous Chandra X-ray observations of this cluster to look for signatures of stellar rotation (e.g., rotation of an accreting white dwarf while accreting from another star), orbital modulations (as the companion star passes in front of the compact object and the accretion disk), and possibly precession of the system.
When a star comes too close to a supermassive black hole at the centre of a galaxy, the strong tidal forces from the black hole’s gravity can rip the star apart. About half of the star’s material falls in towards the black hole, and the other half escapes to infinity. By injecting gas very close to a supermassive black hole, we get a real-time view of how the black hole feeds on the gas. Typically the streams of debris intersect with one another and create shocks, which cause an accretion disk to form. Material spirals inwards through the disk into the black hole. Some of the liberated energy can be used to launch powerful jets. But not all such tidal disruption events appear to produce jets. By studying under what conditions jets can form, we can gain new insights into the jet launching process.
2019 saw the launch of a sensitive new X-ray telescope known as eROSITA, which is predicted to detect hundreds of new tidal disruption events each year. The sample is further augmented by new optical surveys such as the Zwicky Transient Factory. In this project, you will conduct radio follow up of newly-detected tidal disruption events using the Australia Telescope Compact Array and the Karl G. Jansky Very Large Array, to determine under what conditions such events can launch radio jets.
Epoch of Reionisation
Supervisor: Dr Jack Line
Suitability: 3rd year project
The Murchison Widefield Array (MWA) is a low frequency radio (think FM radio waves) interferometer consisting of 2048 dipole antennas, spread over 5km out in the WA outback. It’s capable of imaging huge areas of the sky, but as it’s made up of bits of metal and wires in a harsh desert environment, it suffers from a litany of instrumental effects, which are hard to disentangle from one another. Simulations offer us a cleaner approach to understanding and mitigating these effects but are computationally intense. Many of the calculations are embarrassingly parallel however, so can be optimised to run on GPUs. WODEN is software under development to do just this, with the core code already written in CUDA. In this project, we would aim to add in instrumental effects such as thermal noise and the bandpass frequency response, or consider developing tools to input models of satellite passes and radio frequency interference, to see how they affect our astrophysical observations. This project would suit a student who is computationally strong, with some experience in C very helpful, and would serve as a great introduction to CUDA programming. There is scope to work in python as well (those keen to up-skill in a computational astrophysics project are encouraged to apply!)
Supervisor: Dr Benjamin McKinley
Suitability: 3rd year project
The Murchison Widefield Array (MWA) radio telescope has recently been extended by roughly doubling the maximum baseline length and therefore improving the angular resolution by a factor of 2. This, combined with the implementation of new imaging algorithms that allow us to combine phase 1 and 2 MWA data, has allowed us to make one of the most detailed images yet of our nearest radio galaxy – Centaurus A. The central part of the radio galaxy (near the supermassive black hole) is so bright in the radio band that even our best images are left with low-level spoke-like radial artefacts that limit the science that can be done on the radio lobes. This project will investigate image post-processing techniques to remove these radial artefacts. The initial approach would be to use python tools and Fourier filtering techniques, and then possibly moving on to using machine learning to identify and remove the artefacts. This work will pave the way for multiple publications using the final image.
Supervisor: Dr Anshu Gupta
The high energy photons from the first galaxies escape into the surrounding medium, creating bubbles of ionised gas. As these ionised gas bubbles grew, it only took 1 billion years for the entire universe to go from fully neutral to fully ionised, completing the biggest phase transition in our universe’s history, the epoch of reionization (EoR). Many existing and future radio telescopes such as MWA and SKA are set up to understand this phase transition. However, even after decades of study, we know very little about the protagonists (galaxies) responsible for this phase transition because they remain hidden underneath the fog of neutral hydrogen gas.
In this project, we will use an alternative approach to understanding EoR, by identifying galaxies that “Mimic” the behaviour of galaxies in the EoR and study their detailed properties. The EoR Mimics live 1 billion years after the reionisation of the universe was complete, therefore are not hidden by the fog of neutral hydrogen gas. Using semi-analytic models, we will model the progression of reionisation based on the properties of “Mimic galaxies”. This project will supplement two of the biggest missing pieces in the race to understanding EoR, the number of high energy photons produced by the first galaxies and their fraction escaping into the intergalactic medium.
This project offers unique opportunity to work with data from a number of world-class facilities such as Very Large Telescope in Chile, Keck Telescope in Hawaii, Hubble Space Telescope and soon to be launched James Webb Space Telescope. This project would suit a student with a general background in astronomy and specific interest in observational astronomy. Good programming skills in python and bash scripting would be extremely valuable.
Pulsars and Fast Transients
Over the past several years, the field of Fast Radio Bursts has emerged as an exciting new frontier of astronomy. These intense, energetic bursts are thought to originate from cosmological distances, and they are potential new probes for cosmology; e.g. to measure the baryonic content of the Universe and the magnetic field of the Intergalactic Medium. Yet, the physics governing the origin of these energetic bursts still remains a mystery, despite a continuing flurry of theoretical ideas, and even as interferometric localisations become a routine. The plot has further thickened with no burst emission seen to date at frequencies below ~300 MHz. The co-location of the Australian SKA Pathfinder (ASKAP) telescope and the Murchison Widefield Array (MWA) present exciting opportunities to hunt for low-frequency emission from these enigmatic bursts. Over the past years, the high-time resolution capabilities of the MWA have been pushed to enable voltage trigger and buffer modes. Along with the rapid-response observing mode now possible with the MWA, this can now be exploited for receiving and responding to the trigger alerts from facilities like ASKAP. This project will exploit these new capabilities in the quest to detect low-frequency emission from these bursts. A positive detection would mean the prospects of exciting science relating to FRB emission physics and their propagation and progenitor models, which will contribute to advancing our understanding of these mysterious bursts.
Radio signals produced by high energy (reaching 10^20 eV) cosmic rays entering the Earth’s atmosphere can be detected as very short (order of nanoseconds) radio pulses. Detection of high energy cosmic rays is one of the science goals of the upcoming Square Kilometre Array (SKA). Its low-frequency component (SKA-Low) will be located at the Murchison Radio-astronomy Observatory (MRO) in the Midwest of Western Australia. In order to be able to identify nanosecond signals from high energy cosmic rays amongst other radio signals from other sources, such as radio-frequency interference (RFI), it is important to characterise nanosecond RFI environment at the MRO. The goal of this project is to use data collected by several SKA-Low prototype arrays working at the MRO to classify (ideally by an automatic algorithm) and characterise frequency of occurrence of different types of nanosecond timescale RFI.
The pulsar radio emission mechanism is one of the most celebrated unsolved problems in modern astrophysics. Although it has been known for decades that the magnetosphere of pulsars must be filled with relativistic particles, it remains unclear how these particles, which follow local magnetic field lines, ultimately produce the bright (coherent) emission that we actually observe. One of the major observational clues we have is the so-called “radius-to-frequency mapping”, which allows us to associate observed emission at a given frequency to a specific height above the pulsar’s surface.
In this exploratory project, the student will investigate two types of emission mechanisms. The first is “curvature radiation,” which is an adaptation of synchrotron radiation invoked specifically for pulsar magnetospheres, and which remains the most popular candidate to date. The second is to consider the emission caused by transitions between the available energy states of electrons and positrons in the pulsar’s magnetic field. Even though these transitions are known to produce photons that are far too energetic near the pulsar’s surface (where the magnetic field is strongest), the student will calculate the height at which such transitions become small enough to generate radio emission, and test whether those heights can be reconciled with the heights obtained from other, independent observational constraints.
This project is theoretical and mathematical in nature, and is suitable for students wanting to explore how both special relativistic and quantum effects come together in real, astrophysical environments.
Supervisor(s): Dr Adrian Sutinjo
Description: Fast radio bursts (FRBs) are enigmatic extragalactic radio transients of unknown origin. Lasting for mere milliseconds, they reach us from galaxies billions of light years away. Theories as to their origin include giant flares from magnetars and merging neutron stars. Regardless of their origin, these bursts can be used as impulses with which to probe the structure of matter in the Universe, and they have recently been used to find the so-called ‘missing matter’ in the giant voids between galaxies.
The Australian Square Kilometre Array Pathfinder (ASKAP) is currently the best tool for studying FRBs. The phased array feed (PAF) technology in ASKAP enables localization of the burst which permits follow up with optical telescopes to pinpoint the host galaxy of the burst. Furthermore, ASKAP is in the process of commissioning a burst detection system to enhance the rate of FRB detection. Curtin Institute of Radio Astronomy (CIRA) is engaged in FRB research using ASKAP with a team of researchers and HDR students actively collaborating with CSIRO, Swinburne Institute of Technology and leading international institutions. A key question in FRB research is the emission mechanism of the burst. The current view is that such a luminous burst must be the result of a coherent emission process, similar to a laser in optics or an oscillator in radio frequency. Thermal emission is deemed unlikely because of the extreme temperature required to produce such an intense burst. Coherent emission process is characterized by random arrival of photons which follows Poisson statistical distribution. One of the research topics in FRB pursued at CIRA is detection of this coherent emission statistics.
Detection of random bursts and determination of the statistics thereof is constrained by the time resolution of the instrument. Currently, ASKAP is capable of receiving 400 MHz to 600 MHz of radio frequency (RF) bandwidth centered around 1 GHz to 1.6 GHz. Of that RF bandwidth, 336 MHz band is selected for processing such that the instrumental time resolution is approximately 3 ns. Hence, the statistics of bursts with time separation consistently larger than 3 ns can be inferred but the statistics of random pulses within the 3 ns is obfuscated by the impulse response of the 336 MHz signal bandwidth. The severity of the obfuscation depends on the receiver architecture and can vary from apparent incoherence of a coherent pulse train to an averaging effect which makes signal statistics more difficult to distinguish.
The objective of the project is to study receiver system architectures and signal processing techniques for coherent pulse detection that is less limited by the instrument’s time resolution. There are several ideas to explore. For example, a zero intermediate frequency (ZIF) receiver, similar to a homodyne receiver employed in coherent optical detection and correlation, is affected by the averaging effect of random pulses but does not render them incoherent. We will also explore pulse detection and estimation techniques to maximize the potential of the receiver system architecture.
Neutron stars (pulsars) spin down as the stored rotational kinetic energy is gradually lost in the form of magnetic dipole radiation. Over time, they spin down to rotation periods of several seconds, when the combination of a spin and magnetic field can potentially result in low electrostatic potentials, well below the minimum threshold where pair production and particle acceleration cannot be sustained in the pulsar magnetosphere, thereby stifling the radiation emission mechanism. Detection of such slow-spinning pulsars that are near or below the death line has been difficult in most previous pulsar searches, owing to the presence of low-frequency red noise masking the signature of such pulsars in the Fourier spectral analysis. The recent advent of fast-folding algorithms and their application to pulsar searches with Parkes and LOFAR telescopes have led to the discoveries of pulsars with spin periods longer than ~10 seconds, breaking the long-held record from the 1990s. Data from ongoing pulsar searches at Australia’s Murchison Widefield Array (MWA) are highly amenable to search for such pulsars, owing to the much longer dwell times on the sky than most previous searches. In this project, you will integrate such novel algorithms in the MWA pulsar processing pipelines and undertake initial searches to find more slow spinners that will likely prove valuable to understand how neutron stars spin down as well as the physical processes that drive the generation of electromagnetic radiation from these spinning stars.
Neutron stars (“pulsars”) are extremely compact objects that emit beams of radio waves from their magnetic poles. Due to their rapid rotation (around an offset axis), we detect this beam as a series of regular pulses. However, the process by which the beam is generated in the star’s ultrastrong magnetic and gravitational fields is still poorly understood. Curiously, some pulsars are known to show variations of the emission on microsecond timescales, indicating that the emission process acts on very small (< 1 km) spatial scales. With the advent of latest-generation telescopes like the Murchison Widefield Array (located right here in WA), it is now becoming possible to explore such microstructure for a larger sample of pulsars than ever before. In this theory-based project, you will explore how bursts of emission on microsecond timescales (“microbursts”) would be expected to appear across a wide frequency range within the context of different theories of pulsar emission. Armed with these predictions, you will devise observing strategies that can distinguish between competing models.
The mechanism that generates the radio beams of pulsars remains poorly understood, even after more than half a century of research. This is partly due to the fact that each pulsar is unique, both in the way that individual pulses behave, as well as in an “average” sense (i.e. its profile). Some pulsars even seem to switch pseudo-randomly between two or more “modes”, where each mode is characterised by a distinct profile. Recently, some pulsars have been shown to exhibit a strange behaviour in which the “on pulse” region can shift in rotation phase on a time scale of just a few pulsar rotations, a phenomenon that has become known as “swooshing”. Swooshing presents an interesting challenge to conventional models of pulsar emission, which usually require that the pulsar beam is axisymmetric about the pulsar’s magnetic axis.
Swooshing has only been noted in a few pulsars to date. However, data acquired at ~600 MHz from the Giant Metrewave Radio Telescope in India shows evidence of swooshing in PSR B0031-07, a pulsar for which swooshing has not previously been reported. More interestingly, data taken simultaneously with the Murchison Widefield Array in Australia at ~185 MHz shows that the swooshing is absent at that frequency. Since different frequencies are believed to probe different emission heights above the pulsar’s surface, the frequency dependence of swooshing in this pulsar, coupled with this pulsar’s other well known phenomenology (“subpulse drifting” and “nulling”), can potentially yield powerful insights into the dynamics and behaviour of the pulsar’s magnetosphere. In this project, the student will develop tools to model the swooshing phenomenon, and interpret it in the context of the pulsar’s 3D dipolar magnetic field structure. Depending on the quality of the analysis and the significance of the findings, this project may result in eventual publication.
Fast radio bursts are millisecond flashes of radio waves coming from the distant Universe. Discovered in 2007, the ASKAP radio telescope in Western Australia is a world-leader in detecting them and identifying the galaxies – some billions of light years away – from which they originate. The hunt is on to discover what could possibly be producing such bursts – the progenitor must be about 10km in size, and emit as much radio energy as our Sun produces in a year. However, these bursts also experience a frequency-dependent delay according to the amount of matter they traverse during propagation, allowing them to be used as probes of the structure of the Universe. Importantly, we aim to determine the value of the Hubble Constant, which is currently the subject of intense debate, since measurements from Supernova 1a disagrees with those from the cosmic microwave background. This project – suitable for all levels – would involve using FRB data from ASKAP to answer these questions and more.
Supervisor: Dr Marcin Sokolowski
Suitability: 3rd year, expandable to Honours or Masters
Fast Radio Bursts (FRBs) are one of the most intriguing astrophysical phenomena discovered just over a decade ago. They are very short (order of milliseconds) pulses of coherent radio emission from cosmological distances. Until very recently they were observed at radio frequencies above 1 GHz. However, over the last year detections at frequency band 400 – 800 MHz were reported by The Canadian Hydrogen Intensity Mapping Experiment (CHIME). The goal of the project is to use high-time resolution capabilities of the Murchison Widefield Array (MWA) to discover the first FRBs at frequencies below 300 MHz.
The low-frequency Square Kilometre Array (SKA-Low) is the next-generation radio telescope to be built at the Murchison Radio-astronomy Observatory (MRO) in Western Australia. The telescope will consist of 512 stations composed of 256 dual-polarised antennas each and will observe at frequencies between 50 and 350 MHz.
In 2019, two prototype stations of the SKA-Low were deployed at the MRO and have been regularly collecting data. Multiple long observations (longer than 24 hours) have been conducted with both stations at several frequencies producing thousands of all-sky images in 2-seconds resolution. Several interesting astrophysical events have been identified in these images. In particular, extremely bright pulses from the pulsar B0950+08 have been occasionally detected. In order to understand the physical mechanism behind these events observations with a more sensitive instrument with a higher time resolution are required. Therefore, the goal of this project is to trigger the Voltage Capture System of the Murchison Widefield Array when the extremely bright pulses from B0950+08 (or possibly other objects) are detected in real-time by the SKA-Low precursor stations.
Description: Searching and population studies of radio pulsars is a key science theme for the SKA and its pathfinder facilities. Studies of these exotic objects, originally discovered and investigated at frequencies below 500 MHz, eventually moved to higher frequency bands near ~1-2 GHz in the quest to achieve higher timing precisions and to facilitate deeper searches for new pulsars in the Galactic plane. However, with the resurgence of low-frequency pulsar astronomy enabled by a suite of next-generation radio arrays, and with the low-frequency SKA (SKA-Low) slated to become a potential pulsar discovery machine, it has become imperative to study low-frequency emission properties of pulsars in the frequency bands in which SKA-Low will operate, i.e. from 50 to 350 MHz. This will also serve as important preparatory work for pulsar science with SKA-Low.
This project will build on the ground-work so far in the design, construction and operation of the two prototype stations at the MRO for development work related to SKA-Low, and undertake a focused study of a modest sample of bright pulsars in the southern-sky at frequencies between 50 and 350 MHz. The primary goals include refining the calibration procedures for these two SKA-Low stations and obtaining more reliable measurements of pulsar flux densities and their integrated profiles (i.e. average emission), to investigate the spectral evolution of pulse structure and the spectral nature at low radio frequencies. Considering that the frequencies below 400 MHz is relatively less explored band for the vast majority of southern-sky pulsars, these results will also inform prospective pulsar science with the SKA-Low and possibly our approach to revisit pulsar population studies. The work is anticipated to result in a publication that will report on initial pulsar capabilities of these stations and some early science results.
The clock-like stability of millisecond pulsars, i.e. radio-emitting neutron stars with rotation periods on the order of a few to several milliseconds, makes them especially sought after for high-profile science applications such as searching for ultra-low frequency gravitational waves and probing the state of ultra-dense matter. Searches for millisecond pulsars toward promising candidates selected from the gamma-ray source population of the Fermi Large Area Telescope (Fermi-LAT) have been proving successful, with the discovery of more than 50 pulsars to date from coordinated searches using multiple facilities around the world. The growing observational evidence for a steeper-than-usual spectrum of such pulsars makes low-frequency searches particularly promising to find more such objects, as vividly demonstrated by the recent LOFAR discovery of the fastest spinning millisecond pulsar in the Galactic field known to date. The Murchison Widefield Array (MWA) in Western Australia — a next-generation radio telescope and Australia’s official low-frequency precursor for the SKA — has now been fully geared up for undertaking high-sensitivity targeted searches for millisecond pulsars. Its new capability to reconstruct high-time resolution (~microsecond) voltage time series via novel signal processing algorithms allows retaining optimal sensitivity to the detection of short-period pulsars at very low frequencies. This project will involve performing extensive searches for fast-spinning pulsars (including those in binary systems) toward candidate sources that are carefully selected from the Fermi gamma-ray source catalogue. Targets of particular interest include sources in the far southern sky that are beyond the reach of northern facilities, or low-luminous objects missed in previous (high-frequency) searches. Besides their applicability for high-precision timing programs such as pulsar timing arrays, any newly-discovered pulsars will also prove valuable for understanding complex stellar evolutionary scenarios.
Pulsars are extremely compact, rapidly rotating neutron stars which exist in ultrastrong magnetic and gravitational fields that can’t be investigated in laboratories on Earth. The pulsed radio emission that we detect from pulsars provides a window into the dynamics of the relativistic plasma (magnetosphere) that surrounds them. A major clue to unveiling the high-energy processes involved is the intrinsic polarisation of the radiation, which is both time- and frequency dependent. In this project, you will use ultra-wide-band data from the Parkes Radio Telescope to investigate the polarisation characteristics of PSR B1944+17, an interesting pulsar whose subpulse behaviour is attributed to the popular “carousel model”, but whose frequency-dependent behaviour cannot be easily explained by it. This study aims to show whether the frequency-dependent polarimetric behaviour of B1944+17 can be used to discriminate between competing geometric models for the magnetospheric emission regions. The successful completion of this project is anticipated to result in a journal publication.
PSR J0437-4715, the nearest and brightest millisecond pulsar located just about 150 parsecs from us, has been a celebrated object on several counts: it is a top-priority pulsar for high-profile pulsar timing array experiments in the quest for ultra-low frequency gravitational waves, and it is also a highly sought after target for developing precision timing methodologies and for high-fidelity polarimetric calibration. It is also one of the first pulsars to be studied with the Murchison Widefield Array (MWA), Australia’s precursor for the low-frequency SKA. Over the past several years, regular observations have been made of this fast spinning pulsar at 100-200 MHz band of the MWA, an uncommon observing band for this pulsar, which is routinely studied at frequencies above 1 GHz. However, such low-frequency observations are particularly well suited to study plasma turbulence in the intervening interstellar material and map out its small-scale structure, and to pinpoint the locations of compact dense structures that are sprinkled in the interstellar space. This project will involve a systematic analysis of high-time resolution data recorded with the MWA to study pulsar variability and the time-frequency structure of pulsar’s intensity, to characterise interstellar turbulence and locations of discrete structures along the lines of sight to the pulsar, and also to identify most promising data sets for detailed studies of pulsar emission physics, through studies of phenomena such as microstructure, which is now seen reported in this pulsar’s emission.
All-sky surveys are proven to be the best method for discovering new pulsars (rapidly rotating neutron stars), and a team headquartered at Curtin University has embarked on an ambitious new project to conduct a new low-frequency pulsar survey using the Murchison Widefield Array (MWA, located in the Murchison Desert, WA). The design of the MWA makes it possible to collect the (large volume, ~3 Petabytes, of) data very quickly, but the trade-off for this amazing “survey speed” is the computational effort of processing the data. The last stage of this processing generates a list of pulsar “candidates”, the vast majority of which will be spurious, and which are so numerous that turning to machine learning (ML) techniques is the only viable way to evaluate all the candidates reliably. Although ML software has been developed for other telescopes (e.g. LOFAR in the northern hemisphere), it is likely that the algorithms will have to be adapted to the MWA in order to ensure that real candidates are not sifted out with the false ones. This project will evaluate the viability of the existing software for the use of the MWA survey, and, if necessary, adapt and retrain it in order to maximise the chance of new pulsar discoveries.
Description: Pulsars are fascinating astrophysical objects, extremely dense, built primarily of neutrons, rotating at rates of up to several hundreds of times per second and emitting beacons of radio emission. Furthermore, their physical properties make them also very useful for commissioning new instruments. The goal of this project is to use prototype stations of the low-frequency (50 – 350 MHz) component of the Square Kilometre Array (SKA-Low) to study polarimetric properties of pulsars at low radio frequencies. The digital backend and software have recently been upgraded to enable recording larger bandwidth (about 60 MHz) of the station beam, which can be pointed in an arbitrary direction in the sky. During this project the polarimetric performance of the stations will be characterised and calibrated using a sample of pulsars with well known polarisation profiles. This verification will enable measurements of polarimetric profiles of selected pulsars with yet unknown polarisation properties, which will lead to determination of the emission geometry of these pulsars and possibly other physical parameters.
Cosmic rays are the highest energy particles in nature – yet we don’t know what produces them. Mostly protons and atomic nuclei, they impact the Earth’s atmosphere, and generate cascades of secondary particles that emit a nanosecond-scale radio pulse. Detecting these short pulses can provide the most detailed estimates of the nature of these particles, and the physical processes of these interactions.
This project will investigate either the theoretical or experimental aspects of detecting these cosmic ray radio pulses with the Murchison Widefield Array. Depending on a student’s preferences/abilities, it could involve:
- calibrating a prototype particle detector to identify muons at ground level and trigger radio data:
- testing models of particle interactions at energies unreachable by the Large Hadron Collider, and their effects on the radio emission; or:
- implementing a computationally efficient synthesis algorithm for turning MWA frequency data back to nanosecond resolution.
All projects are adaptable to students of all levels (3rd year, honours, summer project).
Supervisors: Dr Clancy James
Suitability: Honours, 3rd year, Summer
KM3NeT is a cubic-kilometre-scale neutrino telescope under construction at the bottom of the Mediterranean. By detecting the bursts of light produced when these almost massless subatomic particles interact, KM3NeT aims to identify where in the universe they come from. While KM3NeT is still in the construction phase, its precursor facility, ANTARES, has already been operating since 2008.
The recent discovery by the IceCube neutrino telescope of neutrinos coming from a blazar – a supermassive black holes with relativistic jets of matter shooting towards us – has raised more questions than it has answered, a key question being – why haven’t we seen neutrinos the other O~thousand known blazars? This project adapting existing search methods to account for the expected signature of neutrinos from photon-proton interactions in blazar jets that might be detectable by neutrino telescopes. Depending on the level of the project, it may also be possible to access historic x-ray data to search for evidence of these interactions.
Shooting for the Moon – detecting ultra-high-energy cosmic rays with the Five hundred metre Aperture Spherical Telescope (FAST)
Supervisors: Dr Clancy James
The Lunar Askaryan technique is a method to detect the very rare ultra-high-energy, which impact the Earth at the rate of only once per square kilometre per hundred years. By observing the lunar surface with a powerful radio telescope, the entire visible surface of the Moon (20 million km) can be turned into a cosmic ray detector, allowing these extremely rare particles to be studied.
The only current telescope with the power to detect these cosmic rays is FAST, the Five hundred metre Aperture Spherical Telescope, which is now being commissioned in Guizhou Province, China. Curtin University is collaborating with the Chinese National Academies of Science and Shanghai University to use FAST to detect these cosmic ray signals.
The pulses are expected to be short and sharp, lasting only a few nanoseconds – or they would be, if the surface of the Moon was smooth. However, it is not, and the effects of lunar surface roughness on these pulses is unknown. This project would involve using simulations of high-energy particle cascades, together with measurements of the Moon’s surface from lunar orbiting satellites, to determine the effects of lunar roughness on the pulse shape. This would allow an optimum detection algorithm to be developed in preparation for future observations with FAST.
Stars and Stellar Evolution
Some of the smallest stars in our Galaxy, with masses as low as one tenth of our Sun, can produce flares that are ten thousand times more powerful than the solar flares we see on the Sun. These “superflares” are extreme examples of stellar magnetic activity, and impact the atmospheres, habitability, and formation of the surrounding planets, motivating our desire to understand the emission mechanisms that produce these events. The most magnetically active stars produce powerful X-ray/gamma-ray (high-energy) superflares that are detected by telescope (satellites) such as Swift and MAXI. These space missions then send immediate alerts to a network on the ground, allowing telescopes such as the Murchison Widefield Array (MWA) to rapidly begin observing the event.
The MWA is a low frequency (80-300 MHz) radio telescope operating in Western Australia and the only operational Square Kilometre Array (SKA)-Low precursor telescope. The MWA is an entirely electronically steered instrument, meaning that it can ‘slew’ to any part of the sky nearly instantaneously. The MWA also has an extremely large field of view. The large field of view and fast slew time means that the MWA is uniquely placed to provide the fastest follow-up radio observations of transient (explosive or outbursting) events, including flare stars.
For the last year, the MWA has been automatically responding to high-energy stellar superflares detected by Swift and MAXI, obtaining 30 minutes of observations following each outburst. Using these triggered MWA observations, you will investigate whether the same magnetic event that produces bright high-energy superflares can also produce low frequency radio flares, which will aid in providing a more unified understanding of plasma physics in these stellar systems.
Supervisors: Dr Adela Kawka
Suitability: Honours, 3rd year
The majority of stars end their life as a white dwarf. These stellar remnants are burned out cores which are slowly releasing their internal heat. Due to their high gravity, the majority of stars have atmospheres that are hydrogen-rich or helium-rich. White dwarf atmospheres are open to direct investigations and show the effect of a unique range of physical phenomena. One of these is the presence of magnetic fields in a significant fraction of white dwarfs. The presence of a magnetic field is revealed by Zeeman splitted spectral lines. The origin of these magnetic fields remains an open question, although several theories have been proposed. The merger of two stars is the preferred origin based on current observations. One of these is that magnetic fields are observed more frequently in some spectral types compared to others. The European Southern Observatory (ESO) has been obtaining spectra for several decades and has amassed a large archive of data. You will extract spectra from the ESO archive with the aim of searching for magnetic fields and analyse them to determine their atmospheric parameters and measure their magnetic field strength. You will also explore any connection between the incidence and strength of magnetic fields and other white dwarf properties.
Supervisors: Dr Chris Jordan
Suitability: Honours, 3rd year
Asymptotic giant branch stars and red super-giant stars are common sources to power silicon monoxide (SiO) masers. Masers can be thought of as radio-wavelength lasers, and are powered by energetic and exotic conditions in space. In this case, SiO masers are powered by in-falling and out-flowing motions of gas surrounding an evolved star. As not much more is known about these masers, this project presents an opportunity to advance the “big picture” science of evolved stars. In this third year or honours project, the student will process and analyse data collected with the Australia Telescope Compact Array, a radio telescope in northern New South Wales, with approximately 60 targets. Each of the target observations contains multiple spectral line transitions, including each of the v=1, 2 and 3 maser line transitions; any discovery of relationships discovered between the different spectral lines would be an important contribution to the understanding of these masers. In extremely rare cases SiO masers are associated with a star-formation region. Such a discovery would be very important warranting further investigations. In addition, there is a small chance that these data contain SiO masers associated with a star-formation region, which would be an exceedingly rare detection. In the course of this work, the student will develop a good understanding of interferometry and data processing. The results from this work could easily be formatted into a publication, which would be of huge benefit to a student pursuing research into the future with a PhD or masters project. The project is suitable as either a third year or an honours project.
We have discovered an unusual energetic system on the edge of a star cluster in our Galaxy. Preliminary investigations suggest it might be a rapidly rotating neutron star in a binary system with a companion star, where the neutron star occasionally accretes matter from the companion. We have taken new observations with radio and X-ray telescopes to confirm the nature of this interesting object. In this project, you will undertake reduction and analysis of radio (and possibly X-ray) data to investigate the nature of this system.
Supervisor(s): Dr Marcin Sokolowski
Description: The low-frequency Square Kilometre Array (SKA-Low) radio telescope will be the largest radio-telescope in the world. Its unprecedented sensitivity will be result from a huge number of 131072 antennas grouped in 512 stations (each composed of 256 dual polarised antennas). The expected high sensitivity of the telescope will require good performance of at least 99.5% antennas. Therefore, the antennas will have to be regularly monitored and malfunctioning antennas or other components promptly identified and repaired or replaced.
Given the enormous scale of the project and unprecedented number of individual antennas this process has to be fully automatised. The already existing software can identify broken antennas by comparing their power spectra with a template power spectrum and perform basic classification of faults as “no power”, “low power” or “bad bandpass”.
The goal of this project is to further explore and implement a possibility of using the power spectrum information to pinpoint the exact nature and location of a fault, for instance being able to specifically identify that “the connector at the antenna output on polarisation X is loose”. Such a system will significantly speed-up the fault identification and maintenance processes and will be unavoidable in the future when the full scale SKA-Low telescope becomes operational. The scope of the project can be extended to implementation of a fault database and/or inclusion more components of the system.
Invisibility and teleportation might not be in a very distant future considering how rapidly the research on metamaterials has been progressing recently. Metamaterials, also called artificial materials, are composite structured materials made from periodic or random arrays of scattering elements exhibiting properties that are not found in nature. They allow us to build devices interacting with electromagnetic waves, acoustic waves and heat flow to achieve properties otherwise unavailable from ordinary materials.
Even though V. G. Veselago theoretically predicted negative refraction in 1968, it was not until 2000 that the first physical realization of metamaterials was presented by J. B. Pendry and D. R. Smith. Since then, many versions of metamaterials have been demonstrated showing a great control of electromagnetic waves. An electromagnetic wormhole proposed by A. Greenleaf in 2007 describes a tunnel that connects two remote areas of space and supports an uninterrupted propagation of electromagnetic wave inside the tunnel.
Advancement in the metamaterials has led to the development of metasurfaces. They are planar ultrathin metamaterials that enable new physics, distinctly different from layered metamaterials. Since metasurfaces are compatible with on-chip devices, they are the enablers of future technology breakthroughs in high-speed communications and medical imaging, to name a few. The goal of this project is to design and characterize an optical metasurface made of nano-antennas. The problem will be approached from theoretical analysis that will progress to the material characterization using a numerical full-wave simulator.
The project would suit a passionate student with good understanding of electromagnetic fields and waves, basic programming skills and the ability to quickly learn FEKO numerical suit (https://www.altair.com/feko/).
Supervisor: Dr Adrian Sutinjo
The state of polarization of radio sources such as the percentage, type and angle of polarization convey significant astrophysical information. However, determination of polarization information (polarimetry) with a low-frequency phased array telescope depends on multiple steps of calibration and modelling, each of which demands high precision and is challenging. Firstly, low-frequency phased array telescopes are electronically steered such that the primary beam is dependent on the pointing direction. Secondly, unlike single-pixel dish telescopes, a phased array telescope has antenna elements that mutually couple. These factors complicate efforts to repeatably and accurately model the array beam over all frequencies and pointing directions for polarimetry. Finally, calibration of the phased array telescope for polarimetry requires constraining the phase and/or delay between the dual- polarized antenna, which in the case of the Murchison Widefield Array (MWA) are orthogonally polarized dipoles (called “X” and “Y”). For our purpose, we call this quantity X/Y phase. We note that similar considerations apply to the next generation low-frequency radio telescope, the low-frequency Square Kilometre Array (SKA-Low).
X/Y phase calibration is not critical in intensity-only observation or imaging. In this case, the X dipoles may be calibrated separately from the Y dipoles using an unpolarized sky model. The relative phase between the two dipoles is not critical. However, in polarimetry, the polarization angle and type of polarization cannot be correctly inferred without proper X/Y phase information. Astronomical calibration of X/Y phase could be achieved by observing a bright source with well-known polarization properties. However, such sources are less well-characterized at low frequencies and do not transit at zenith such that calibration of X/Y phase is dependent on the quality of the beam model. It is highly desirable that the X/Y calibration be separated from the beam model to minimize uncertainties and systematic errors.
The objective of the project is to explore methods to calibrate X/Y phase by direct measurement on site and devise the most appropriate technique given the conditions and constraints of the telescope operation in Murchison Radio-astronomy Observatory (MRO). The physical mechanism that gives rise to the direction-independent delays between the X and Y dipoles in the MWA is no different than that which produces the X and Y delays separately. They primarily depend on the relative group delay due to the electronic signal chains and the cable lengths. For a single MWA X/Y dipole, this quantity is measurable directly by injecting in phase RF signals into the dipoles and measuring the X/Y phase at the MWA correlator. For the MWA tile (an entity of 4×4 dual-polarized dipoles), the signal should be simultaneously fed into all elements. This requires further considerations and proper engineering to ensure that the method of injection and measurement is easily deployable, is repeatable and minimizes potential interference at the MRO. We fully expect that X/Y phase calibration and the techniques arising from this project research will be applicable to SKA-Low polarimetry.
Computational Quantum Physics
Students interested in computational or theoretical physics are encouraged to consider projects in the Theoretical Physics Group. This is a research intensive group, which was (2007-2013) a node of the ARC Centre of Excellence for AntimatterMatter Studies. It specialises in the field of Quantum Collision Physics. Such processes occur all around us, and include all chemical reactions. More specifically, our area of expertise is for projectiles, which include electrons, positrons, photons, protons and antiprotons, colliding with atoms, ions and molecules. Applications include astrophysics, fusion energy, lighting, material and medical diagnostics.
Presently, there is considerable demand from astrophysicists and fusion physicists for the generation of electron/positron-atom/molecule collision data. Depending on the student’s background knowledge and scope of the project, individual research projects will range from data generation and evaluation, utilising super computer facilities, through to extending the computational capacity to be able to tackle new collision problems. The expectation is that the research outcomes would be published in the best physics journals. The specific details of the project will be determined by discussion with the particular staff of the Theoretical Physics Group. Some examples are listed below.
Modelling collisions of ions with atomic and molecular targets is important for a variety of applications ranging from astrophysical processes and nuclear fusion to modern cancer treatment techniques like proton therapy.
Proton therapy is used to destroy deep-seated cancer cells. It can precisely target the location, size and shape of the tumour, limiting damage to surrounding healthy tissue. When fired into living tissue, a beam of protons deposits most of its energy at a very specific depth that depends on its initial energy. This makes minimal damage to surrounding organs in front of the tumour while delivering almost zero radiation after the tumour. Such precision is not possible with other radiation treatments such as X-ray therapy. Proton therapy requires careful treatment planning based on theoretical depth-dose simulations with a mm accuracy. This requires precision data on relevant ion-atom and ion-molecule collisions.
In fusion plasmas injection of proton beams is used for diagnostics. Certain materials like Be will be used as the shield for the first wall of the International Thermonuclear Experimental Reactor (ITER) and an ITER-like wall is already under operation in the Joint European Torus (JET). Erosion of the first wall releases atoms (and several molecular species), which eventually lead to the presence of fully-stripped ions in the plasma core. The diagnostics of impurity density and temperature in the plasma core is carried out by applying a charge exchange spectroscopy (CXS) technique, where a fast beam of H atoms collides with the impurity ions, leading to the electron capture (EC) reactions. The diagnostics is based on emission, usually in the visible spectrum, of the resulting excited ions. The application of the CXS diagnostics requires the knowledge of state-resolved EC cross sections, which are in general difficult to measure.
A number of theoretical approaches have been developed to model ion collisions with atoms and molecules. At moderate collision energies all open reaction channels including elastic scattering, electron capture and ionisation are interdependent and have significant contributions. However, most of the theories are based on different Born approximations: first- and second-order plane wave, distorted wave, etc. Furthermore, only a few of them takes more than one populated electronic state into account: these theories usually focus on the ground state (initial and final states), while experiments integrate over all final populated electronic states. As a result, there is no satisfactory theoretical description of available experimental data. Furthermore, significant discrepancies remain between the results due to the lack of convergence in terms of included states.
The aim of the project is to provide accurate data on heavy ion collisions with atoms and molecules required in radiation dose calculations for hadron therapy and plasma diagnostics. Calculations will be performed using a semiclassical wave-packet convergent close-coupling (WP-CCC) method recently developed in our group. The method solves the Schrödinger equation for the ion-atom or ion-molecule system by expanding the total scattering wave function in a two-centre basis. The wave functions representing the target and hydrogen-like ion formed after electron capture, are the true eigenfunctions for the negative-energy states and orthonormal stationary wave packets for positive-energy states resulting from the discretization of the continuum. This leads to a set of coupled differential equations for the transition probability amplitudes, which are used to calculate the cross sections for elastic scattering, target excitation, and electron capture by the projectile and ionisation.
Cross sections for antihydrogen formation are of particular interest to the ALPHA collaboration, which requires the production of near zero energy antihydrogen. Production of slow antihydrogen atoms is one of the prerequisites for experimental verification of the materantimater equivalence principle. There are two experiments with antihydrogen planned for the near future at CERN, AEGIS (Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy) and GBAR (Gravitational Behaviour of Antihydrogen at Rest). The aim of these experiments is to measure the freefall of antihydrogen in order to make direct measurements of the freefall acceleration constant of antimatter in the gravitational field of Earth. To observe the free fall the antihydrogen has to be created at rest or cooled to extremely low energies (a few neV). With new developments in antiproton cooling techniques cryogenic temperatures became achievable.
Therefore, formation of antihydrogen in ultra-low energy positronium-antiproton collisions with its very large cross section emerges as a primary source of antihydrogen. Antihydrogen can be created with the use of antiprotonpositronium collisions. Large cross sections are achieved when positronium is in a Rydberg state. The aim of the project is to use the two-center convergent close coupling (CCC) method to model antiproton collisions with Rydberg positronium and calculate the antihydrogen formation crosssections at ultra low energies.
- Review the literature.
- Learn how to use supercomputers to run locally developed codes.
- Calculate total cross sections for antihydrogen formation at low energies.
The Theoretical Physics Group has been engaged in the biggest scientific research project on the planet, which is the building of the next generation fusion reactor known as ITER, see http://iter.org. The goal is to produce fusion energy as it happens deep in the core of our Sun. Our contribution has been to provide collision data of interest to the plasma modellers who are trying to understand all of the physics that will follow the fusion process.
Recent example is beryllium: it has been determined that beryllium will be a substantial component of the first wall, and hence reliable electronimpact cross sections for this atom and all of its ions are required by the modellers. Collision data for many more atoms and molecules are required for modelling the ITER plasma. Our aim is to develop a computer code that is capable to model collisions with a much wider number of atoms and molecules than the present version of the CCC code allows for.
An even more difficult task is to extend the CCC code to study collisions with molecules. We are especially interested in the molecules that are present in ITER plasma: BeH, BeH2, Li2, Li_H, etc. We have already developed a computer code that produced the best in the world result for H2+ and H2molecules and now aim to extend it to more complex systems.
This project will contribute to the International Atomic Energy Agency fusion research and will be our contribution to the Coordinated Research project (CRP): “Atomic data for Vapour Shielding in Fusion Devices”.
Here are theoretical and code development projects that you can participate:
Electron collisions with atoms
The project aims to provide a comprehensive set of collision data for electron collision with tin and gallium atoms. We will use the relativistic formulation of the CCC method (RCCC) as Ga and Tn are relatively heavy atoms. Both atoms have p-electron in the open shell, one for Ga and two for Tn, and show substantial fine-structure splitting that indicates that relativistic effects will play important role in modelling of atomic structure and collision processes.
Electron collisions with molecules
The present version of the CCC code will be extended to more complex molecules, such as Li2, LiH, etc. The aim is to provide a comprehensive set of collisions data relevant for fusion research. This includes a set of elastic and momentum transfer, ionization, excitation and dissociation cross sections. The study of nuclear motion will allow us to provide a set of fully vibrationally resolved cross sections.
- Understand what ITER is all about.
- Understand the physics and the mathematical model behind the computer code.
- Learn how to use supercomputers to run locally developed computational codes to determine the required data to a required accuracy.
- Disseminate the data to existing databases for ready access to fusion researchers worldwide.
Modelling positron transport in various media is of immense importance for applications as diverse as atmospheric and astrophysical research and studies of radiation damage in tissue. Accurate modelling requires accurate collision data: cross sections for all relevant collision processes. We have developed the best in the world computer code (CCC) to model positron collision processes. The next step is to make the code more general and capable to model collisions with arbitrary atom or molecule. We will have a special emphasis on study of the collisions with biologically important atoms and molecules.
- Review various applications of positrons
- Understand the physics and the mathematical model behind the computer code.
- Learn how to use supercomputers to run locally developed computational codes to determine the required data to a required accuracy.
- Disseminate the data to existing databases for ready access to researchers worldwide.
State-selective electron capture in fully stripped neon ion collisions with hydrogen for charge-exchange spectroscopy
Modelling collisions of neon ions with hydrogen is important for understanding X-ray emission from comets and planets in the solar system. In addition, diagnostics of fusion plasma in the International Thermonuclear Experimental Reactor (ITER) and the Joint European Torus (JET) is performed using charge-exchange spectroscopy (CXS), where a beam of H atoms collides with impurity ions, including highly-charged Ne10+ ions, leading to electron capture (EC). The CXS is based on emission of the excited Ne9+ ions. The application of the CXS requires the knowledge of state-selective EC cross-sections, which are difficult to measure. This project aims to perform accurate calculations of state-selective cross-sections for EC in Ne10+ collisions with hydrogen using a wave-packet convergent close-coupling (WP-CCC) method recently developed in our group [Faulkner et al., Plasma Phys. Control. Fusion 61 (2019) 095005]. The method solves the three-body Schrödinger equation for a fully-stripped ion-hydrogen atom system by expanding the total scattering wavefunction in a two-centre basis of pseudostates. This leads to a set of coupled differential equations for the transition probability amplitudes. The latter are used to calculate the cross sections for elastic scattering, target excitation, and EC by the projectile and ionisation.
The heart of a molecular dynamics simulation is the selection of an appropriate interatomic potential for the calculation of forces and energies. Carbon has proved one of the most difficult elements to describe due its flexible bonding and long-range interactions. More than 45 different potentials have been proposed for carbon, and presently there is no universally suitable potential. This project will use high-performance computers at the Pawsey Centre to perform benchmarking of crystalline structures of carbon. The data will be uploaded onto a website (www.carbonpotentials.org) to enable researchers from around the world to evaluate carbon potentials. This project is suitable for students with an interest in computing and chemistry. If time permits, the project can be extended to consider molecular carbon nanostructures, such as fullerenes.
Unexpected plastic deformation in diamond rods has been observed by researchers at University of Technology, Sydney. Collaborative simulations performed at Curtin suggest than this behaviour is due to a new phase of carbon which combines graphitic and diamond bonding. We have named this phase O8-carbon due to the orthorhombic symmetry and 8 atoms in the unit cell. In this project the student will explore O8-carbon using a combination of density functional theory (DFT) and molecular dynamics. The simulations will involve calculation of the energy barriers to transform diamond into this new phase, as well as the thermal stability and mechanical properties of O8. This project is suitable for a student with an interest in materials modelling. Training in computational modelling will be provided, and prior experience is quantum-mechanical methods is not required.
Diffraction is a common experimental tool for measuring the size of graphitic crystallites, but interpreting the data is a challenge. For decades the Scherrer equation has been used for the analysis of diffraction data, with little attention paid to what are effectively empirical constants. Computer-generated diffraction patterns offer a way forward by correlating the shape of the pattern with the known crystallite size. In this project, the Debye equation will be used to compute the diffraction pattern of graphene stacks and flakes of different curvature and size. This project is suitable for a student interested in the use of computers to interpret experimental data. Some of the calculations will be performed in MATLAB, while the larger systems will use an open-source package.
Atomistic computer models are often restricted by finite-size effects whereby the small number of atoms affects the properties. To avoid this problem, we have constructed a set of very large carbon structures containing one million atoms. These are the first of their kind, and are more than 10 times larger than typical simulations. In this project, the student will analyse the structures to determine how density controls the transformation from a porous material into a dense, glassy solid. Properties to compute include pore size distribution, diffraction pattern, elastic constants, and TEM (transmission electron microscopy) images. Students with a strong background in coding can extend the project to develop a tool to extract the crystalline size directly from the structure.
Supervisor: Assoc Prof Nigel Marks
Nanodiamonds recovered from meteorites contain trace amounts of all five stable noble gases. Sophisticated laboratory techniques have been developed to extract the gases, with isotopic analysis proving that the nanodiamonds are older that the solar system. To interpret the experimental data we have developed a molecular dynamics approach which accurately reproduces experimental data for helium and xenon. In this project the student will extend the methodology to another noble gas, such as neon, argon or krypton. Specific tasks include parametrizing a gas-carbon potential, constructing a set of candidate structures via ion implantation and computing thermal release temperatures. The formalism is amenable to a processor-farming approach, and hence this project is particularly suitable for a student interested in cloud-computing and task automation.
The Hydrogen Storage Research Group (HSRG) specialises in the study of materials for thermal energy storage applications. Past studies have focused on employing the thermodynamics of reversible absorption and desorption of hydrogen from metal hydride compounds (e.g. MgH2 and NaMgH3) to store energy at temperatures of above 300 °C. This thermal energy may be produced by employing concentrating solar power (CSP) to heat the material, a process that is already used to produce electricity in many sites around the world, for example the Crescent Dunes Facility in Nevada, USA. The thermal energy storage systems are used to store the excess heat collected during the day to produce electricity at times of low solar exposure. To improve the efficiency of thermal energy storage systems, that is to produce electricity for longer periods of time, materials that can operate at elevated temperatures are required to be developed. This includes identifying possible compounds, synthesizing and characterising their physical properties.
A number of projects are available in the HSRG to develop novel metal hydrides and metal carbonates that can be used as thermal energy storage materials. Projects would include the synthesis and characterization of novel metal hydrides and metal carbonates for potential incorporation into large scale industrial plants. Thermodynamic determination of the enthalpy and entropy of gas desorption by physical measurements and theoretical calculations must be undertaken to identify technological application, while crystallographic characterization by powder X-ray diffraction will be used to study these materials. A variety of projects are available and can be tailored to suit individual studies. This project is likely to lead to a publication in an international peer reviewed journal.
New battery technologies offer the possibility for greatly enhanced energy storage capacities. High energy density is critical for most technological applications, such as for portable electronics and vehicles, i.e. more energy in a form that weighs less and takes up less space. Further breakthroughs are required to bring new batteries to reality, especially with regard to the electrolytes. Here, solid-state electrolytes could allow electrochemical reactions to proceed where liquid electrolytes fail, also providing higher electrochemical stabilities and enhanced safety.
Our group has synthesised new types of solid-state electrolytes that have interesting dynamics within the crystal structure. The anions within the structure rapidly reorientate up to 1E10 times per second, promoting the migration of cations, such as Li+, within the structure. These types of solid-state ion conductors have ion conductivities on par with liquids! The challenge is improving the ion conductivity at room temperature for battery applications.
This project will focus on the measurement, characterisation and analysis of electrochemical measurements on new solid-state ion conductors. The materials are air-sensitive and will be handled within an argon-filled glovebox. Measurements will be undertaken using newly acquired equipment by using electrochemical impedance spectroscopy. This data can be collected as a function of temperature by heating the air-tight electrical cell to multiple temperatures. Further analysis will be undertaken to test the voltage-stability and chemical compatibility of the solid-state electrolytes with typical anion and cation materials. It is expected that high-impact peer reviewed publications will result from this project.
Many countries, including Australia, have announced their strategy to include Hydrogen as a major part of their energy portfolio. Japan is one country that has announced they are making hydrogen their primary fuel of the future but are currently unable to produce enough hydrogen to meet demand, and as such must rely on importation. Australia is positioned to be able to produce renewable hydrogen and be a key global exporter, although an efficient (high density) means of carriage is required.
This project aims to develop a new method of producing, storing, and exporting green hydrogen. Metal hydrides produce pure H2 upon addition of water forming a metal oxide. This process is irreversible under moderate conditions, therefore this procedure is not economically or environmentally viable for commercial application. This project entails the development of a method for making the hydrolysis of metal hydrides into a reversible reaction. A variety of synthesis techniques will be explored including wet-chemistry, gas-solid reactions, electrolysis and mechano-chemistry, while a number of analytical techniques will also be required to determine the products. Additional scope is directed towards theoretical calculations to identify possible synthesis routes.
A number of thermal energy storage systems and methods of producing green hydrogen have recently been commercialised or promoted. The direct processes involved in many of these systems are currently under patent or IP protection and so are difficult to assess. This project involves fundamental physical calculations to determine the underlying thermodynamic properties and cost calculations of these technologies.
The Hydrogen Storage Research Group (HSRG) have been developing thermal batteries that will enable 24/7 energy supply using renewable energy sources. These batteries will supply power while other energy sources are showing intermittency problems. The HSRG have recently developed a 4th prototype that stores 2 kg of thermal storage material although to be technologically viable, around 4 tonnes of active material will be required. This project will focus on further development of current systems which involves upscaling to larger quantities of thermal storage material, improving thermal management to improve efficiency and upgrading the heat transfer fluid system. The scope of this project can be specifically tailored to include theoretical and experimental studies.
John de Laeter Centre (experimental physics)
Supervisor: Dr William Rickard
A FIB-SEM combines nanometre resolution imaging with precision patterning of a focussed ion beam enabling the instrument to manipulate a sample at very fine length scales. The Tescan Lyra FIB-SEM, located within the John de Later Centre at Curtin University, is a state-of-the-art instrument that is used for advanced microanalysis in 2D and 3D as well as high precision site-selective sample preparation.
Surface analyses (electron and ion imaging, chemical mapping (EDS), crystallographic mapping (EBSD)), sub-surface analyses (3D imaging, 3D EDS, 3D EBSD) and unique in-situ ToF-SIMS analyses are able to be correlated with site specific atom probe tomography or TEM results which enables a thorough characterisation of highly complex materials on a wide range of length scales.
In this project the student will get trained to operate the FIB-SEM and will run a series of experiments in order to optimise the data collection and data analysis methods for 3D imaging and 3D microanalysis. Other projects involving the ToF-SIMS will also be available.
Supervisor: Dr David Saxey
Atom Probe Tomography works by dis-assembling materials one atom at a time, and using software to reconstruct their original 3D locations and chemical identities. It is a powerful tool for the characterisation of materials – unique in its ability to provide three-dimensional chemical information on the atomic scale. Although the technique has existed for some time, the past ten years have seen a rapid uptake, with over 100 machines now installed in laboratories around the world. The range of materials studied has also grown; from metal alloys, to semiconductor device structures, ceramics, and more recently geological materials.
The Geoscience Atom Probe facility, housed within the John de Laeter Centre, operates the first atom probe microscope to be dedicated to geo materials. As such, there are many new and interesting applications within this field, and many opportunities for original research into outstanding scientific problems. In addition to these applications, the physics of the technique itself is also an active area of research, with open questions surrounding the evaporation and ionisation of atoms from the sample under extremely high electric fields. There are also interesting problems in the analysis of the 3D chemical datasets, which can range in size beyond 10^8 atoms.
We are providing a number of opportunities for interested students to contribute to projects within the Geoscience Atom Probe facility, which would include the acquisition of atom probe data, as well as analysis and interpretation of the datasets. There are also opportunities to develop techniques and analysis tools to provide new methods of extracting information from the 3D data.
Supervisor: Prof Charlie Ironside
Micro and nano fabrication is a key enabling technique for many aspects of electronics, photonics and biotechnology. Much of modern technology relies on micro and nanofabrication including the CMOS devices used in mobile phones and laptops. Plus nanofabrication is now extensively employed to explore new nanostructures that reveal the quantum nature of the physics underlying many novel devices. In this project we will explore the use of focussed ion beams (FIB) for creating novel nanostructures. The FIB tool can be used mill features less than 100 nm on a variety of materials making it a very versatile tool for quick prototyping of new nanofabricated devices and structures. We will use FIB to make structures with features less than 1 micron on 2 dimensional semiconductors such as grapheme and Gallium Selenide (GaSe) and on optical fibres.
Supervisor: Dr Matthew Rowles
X-ray diffraction provides a direct probe of the atomic structure of materials. It can be used to provide information on bond distances, crystallite size, thermal expansion, and amounts of phase in a mixture, amongst other parameters of interest. In carrying out these measurements, there are various experimental, specimen, and modelling effects that can affect the accuracy and precision of the derived values. The projects offered in this area investigate data collection and analysis techniques and how they can be optimise to give the best answers. Good programming skills are required for some of the projects.
There are several projects within this application area:
- Effect of step size, counting time, and angular range on quantitative phase analysis accuracy and precision
- Absolute quantification of in situ X-ray diffraction of high thermal expansion materials
- Effect of variable counting time and step width on structure refinement from powder data with large detectors
- Automatic background removal and phase change identification in in situ X-ray diffraction data
Developing a 3D reconstruction technique of a uranium-bearing rock by transmission electron microscopy (TEM) tomography
Supervisors: Dr Zakaria Quadir, Dr David Saxey and Dr William Rickard
Uranium is a key mineral for our national economy. This project involves developing methods for 3D tomography at the nanoscale to determine the location of uranium-rich sites in within a uranium-bearing rock, and thus facilitate to develop a uranium liberation processes for the WA minerals industry. This project involves TEM data acquisition with the FEI Talos TEM in the Microscopy & Microanalysis Facility (MMF) within Curtin’s centralised research infrastructure hub JdLC, and then, exploit the advanced capabilities of the 3D reconstruction software to develop a data visualization techniques.
Remote Sensing and Earth observation from space Prof David Antoine , Remote Sensing and Satellite Research Group ( RSSRG )
Prof David Antoine specializes in the use of satellites and in situ optical data to understand oceanic processes and their links to climate and environmental changes. This work is largely based on data from NASA and ESA satellites, and our findings feedback into processing algorithms for these missions.
A number of Earth observation satellites orbit around our Planet, carrying “radiometers”. These instruments record the spectral radiance at the top of the atmosphere, which, after appropriate corrections, provides the spectral reflectance of the upper ocean layer. From the spectral changes of this reflectance, one can derive a number of key environmental quantities, such as the chlorophyll content of phytoplankton (the primary producers of the sea, underlying essentially all oceanic food webs), the sediment load (e.g., as produced by dredging operations), or the absorption by coloured dissolved organic matters (those substances that make the Swan river look like tea).
Key to using satellite observations is having in situ data for validating them. Prof. Antoine has obtained a unique time series of optical data in the Mediterranean Sea through the deployment of a large bio-optical Mooring. (BOUSSOLE: http://www.obs-vlfr.fr/Boussole/), and has also time series of similar measurements off Rottnest island, Perth.
Possible subjects are summarised below but, if you have any other idea that you think might involve satellite remote sensing, please feel free to come and discuss it. We can design a project to suit your interests.
Validation of satellite observations off Rottnest Island, Perth
The RSSRG has deployed a profiling mooring off Rottnest Island, Perth. This new equipment collects vertical profiles of optical and biological properties of waters at that site. The data set allows deriving the water reflectance, which can then be compared to the same parameter as delivered by satellite remote sensing instruments, in particular the “Ocean and Land Colour Imager” (OLCI) launched in 2016 by the European Space Agency (ESA) on board the Sentinel-3 satellite. The work will consist in processing the profiling mooring data set, sourcing the corresponding data from the satellite observations, and evaluating how well they match. The results will be communicated to the “Sentinel validation team”, which is an international group of scientists working on the global evaluation of the quality of OLCI products, under ESA leadership.
Spatial and temporal scales of variations of phytoplankton off WA
Physical and biological properties of oceanic waters off Western Australia (WA) are largely influenced by the Leeuwin Current (LC), which is the major southward flow of warm, low-salinity tropical waters along WA coasts. It varies on inter-annual to decadal time scales, in particular under influence of the El Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO). Mesoscale eddies in the Leeuwin Current have profound influence on temperature and chlorophyll distributions in the region. For example, the warm-core eddies that spin off from the LC have a significant effect on the level of productivity in the mid-west region. Here we propose to study the spatial and temporal scales of variation of phytoplankton off WA through the use of NASA and ESA satellite ocean colour remote sensing products. Archives of such products date back to 1998 and, therefore, allow studying seasonal, inter-annual and decadal changes.
Optical properties of waters off WA
Phytoplankton are the microscopic unicellular algae living in the top layers of the ocean, where light and nutrients are available for these organisms to develop through the photosynthetic process. They are the basis of the marine food web and are therefore a key component of marine ecosystems. The RSSRG has deployed a profiling mooring off Rottnest Island, Perth, which collects vertical profiles of water optical and biological properties in view of getting better insight about time changes of phytoplankton and their distribution within the water column. Among these properties are the phytoplankton chlorophyll fluorescence, which is a proxy for phytoplankton biomass, the particle optical backscattering coefficient, which is a proxy for the amount and type of particulate matter in the water, and the absorption coefficient, which provides additional information on the influence of particulate matter (in particular phytoplankton) on the water optical properties. The work we propose here would combine these different parameters to provide insights into phytoplankton dynamics on that site.
The underwater light regime in the Eastern Indian Ocean off WA
In May-June 2019, the RSSRG participated to a 1-month research voyage on R/V Investigator (see links below), exploring waters of the Eastern Indian Ocean (EIO) off WA, from 40°S to 10S along the 110°E longitude. During this voyage we have sampled optical and phytoplankton properties of the upper (0-200m) water column, and we have also measured the underwater light field and the light (the “radiance”) leaving the surface ocean. The latter is the one that then travels through the atmosphere and is recorded by satellite instruments orbiting around the Earth. Here we propose to work on comparing various ways of getting the “water-leaving radiance” either from extrapolating measurements taken by instruments that are deployed below the surface or from instruments that are installed on the ship and measure the water-leaving radiance from above the surface.
Net Community Production in the Eastern Indian Ocean
Supervisor: Charlotte Robinson
In May-June 2019, the RSSRG participated to a 1-month research voyage on R/V Investigator (see links below), exploring waters of the Eastern Indian Ocean (EIO) off WA, from 40°S to 10S along the 110°E longitude. One objective of the expedition was to study the biological carbon pump at the base of the food chain by measuring the marine microbial primary productivity using radiocarbon isotopes (14C) and net community production with a state-of-the-art equilibrator mass-inlet spectrometer system (EIMS) that measures dissolved oxygen-argon ratios. These measurements, combined with ancillary measurements of temperature, salinity, available light, physical mixing and phytoplankton characteristics such as community composition, size, carbon content and pigmentation will contribute to a mechanistic understanding of carbon export production in the oligotrophic Eastern Indian Ocean. Working with Dr Charlotte Robinson, the student will learn to quality control oceanographic data, compute net community production using the EIMs data and other physical and chemical oceanographic data and contribute to a journal publication on the biological pump and carbon export potential of marine microbes in the Eastern Indian Ocean. Interested students should be comfortable with working in and processing data in Matlab, Python or R.
The two extremes of cloud cover are totally clear skies or total cloud cover. With ~ 70 % of the Earth cloud-covered at any time, partial cloud cover is the most likely condition. The global modulating effect of clouds on climate is a key controller of global warming with, in principle, a 4% change in cloud cover able to reverse the current impact of CO2 warming. The temperature of the land surface due to incoming solar radiation is reduced the higher the surface reflectivity in the visible spectral region. However, the ability of the land surface to cool is enhanced if the emissivity of the surface is high in the infrared region of the spectrum. The interplay of these two physical processes is important in understanding global warming and climate change but also in phenomena such as the urban heat island effect. For example, greening suburbs increases their overall infrared emissivity. The project will involve field campaigns using infrared sensors to explore the subtleties of these thermodynamic processes for different surfaces and environmental conditions.
Optical communication links (eg using encoded laser beams) provide much higher bandwidths than are possible to achieve with radio communication links such as wi-fi. For high bandwidth duplex optical communications between the surface-based facilities and orbiting satellites, cloud cover and atmospheric turbulence are serious limiting operating factor frequently requiring use of multiple well-spatially separated ground stations. However, operators of these systems are able to function when thin clouds are present. Deciding in advance as to whether a cloud is thin or thick is more challenging, particularly at night time. The approach is to employ ground-based infrared remote sensing to establish the relationship between a cloud’s optical transmittance (optical depth) and its infrared emissivity since the latter can be measured. The project will use infrared sensors to investigate water and ice clouds and validate their properties. The project is linked to the establishment of ground-based infrastructure for an Australia-Japan collaborative Regional Engagement Fund initiative.
Centre for Marine Science and Technology
I carry out research in the Centre for Marine Science and Technology (CMST). My main area of interest is underwater acoustics, although I also dabble in underwater vehicles, oceanography, musical acoustics, and signal processing in general.
Acoustic particle velocity sensors
Underwater sound measurements are usually carried out using hydrophones that measure sound pressure, however fish and some other marine animals sense the motion of water particles caused by the sound waves instead. Sensing particle velocity is more difficult than sensing pressure but has the advantage of indicating the direction the sound wave is travelling in, and for environmental applications provides a direct measure of what animals with this type of hearing are sensing. The aim of this project is to develop and characterise an accelerometer based particle velocity sensor suitable for use in a laboratory tank.
Modelling mechanical stresses in animals exposed to very loud underwater sounds (with Assoc. Prof. Rob McCauley)
The aim of this project is to model the internal mechanical stresses in marine species such as zooplankton, shellfish and fish that result when these animals are subject to the very loud sounds produced by the airgun arrays that are used for offshore seismic exploration. This would involve the application of analytical and numerical techniques of increasing sophistication, and has direct application to current concerns about the environmental impacts of these surveys.
Using propeller noise as a sound source for subbottom profiling
Boat propellers generate high levels of underwater noise over a wide frequency range. It should be possible to use this noise as a sound source for a simple sonar that would provide information about the layering of sediments in the top few metres of the seabed. A preliminary experiment, carried out in 2009, showed some promise, and it would be good to develop this idea further.
Ship noise in Australian marine habitats
The marine soundscape can be split into its biophony (the sounds of whales, dolphins, fish, crustaceans etc.), geophony (the sounds of wind, rain, waves, ice etc.) and anthrophony (the sounds of human/industrial operations). Ship traffic is the most persistent source of man-made noise in the marine environment—with potentially significant bioacoustic impacts on marine fauna, most of which rely heavily on acoustics for their critical life functions. CMST has recorded the marine soundscape around Australia for 15 years at various sites. Using publicly available position logs of large vessels, we can 1) compute received levels of individual ships, 2) calculate source levels of individual ships by sound propagation modelling, and 3) determine the contribution of shipping to the local noise budgets. This project will suit a mathematically skilled student with some experience in scientific software development, data analysis and numerical modelling. An acoustic background is NOT necessary.
Black Cockatoos Calling
We are looking for two Honours students interested in studying cockatoo acoustics for a year. Black cockatoos, Calyptorhynchus sp., are endangered and specially protected in Western Australia. There is a regular citizen science survey, called the Great Cocky Count, which has provided crucial information on black cockatoo populations.
Cockatoos are noisy. They produce sounds that differ by species, age, gender and behaviour. We want to explore whether passive acoustic listening can provide additional data on population size, distribution and demographics. We have preliminary recordings of Carnaby’s cockatoos near the Curtin University Bentley campus, and of red-tailed black cockatoos in John Forrest National Park. The Honours students will be involved in additional field work, including recordings and visual observations, establish a call repertoire of these two species, correlate calls with behaviour and demographic parameters, and potentially look at changes in calling behaviour as a function of human disturbance.
The bioacoustic repertoire of Australian striped dolphins (Stenella coeruleoalba)
Striped dolphins (Stenella coeruleoalba) are an offshore, pelagic species of dolphin, which are most commonly seen along the edge of the continental shelf or over deep-water canyons. We have little information about the Australian population. Threats are direct catches, fisheries bycatch and pollution. Curtin University’s Centre for Marine Science & Technology has photographic and passive acoustic data for this species, and we are looking for a 1-year Honour’s student to study the bioacoustics of Australian striped dolphins, with the overall aim of characterising their sound repertoire to aid long-term passive acoustic monitoring. We are hoping to fill this position as soon as possible, January 2017 the latest. Depending on timing, there might be opportunities for additional field work.
Variability in acoustic tag performance and detection range
Acoustic tags are increasingly used to track behavioural patterns of numerous marine species, but the long-term performance of the pinging tags and stationary receivers is rarely tested. Biofouling of the receivers, for example, holds potential to significantly reduce performance, affecting the results of marine studies. This project aims to assess directionality, source levels and detection ranges of some acoustic tags in a practical environment and the propagation of their signals. A number of acoustic tag receivers are located at the Mullaloo Beach Lab site. Working in collaboration with Mullaloo Beach Surf LifeSavers tags are to be periodically located in and around the array while tag source levels are also tested. Matlab programming skills will be developed. Kayaking experience preferred.
Acoustic remote sensing of the marine environment
I carry out research in the Centre for Marine Science and Technology. My main area of interest is underwater acoustics, particularly acoustic remote sensing of the marine environment.
- Measuring and modelling of seafloor backscatter
- Detection of marine gas seeps using acoustic techniques
- Underwater acoustic monitoring of marine fauna
Stereoscopic 3D Displays are increasingly being used in a wide range of application areas including scientific visualisation, industrial automation, medical imaging as well as gaming and home entertainment. The Centre for Marine Science and Technology (CMST) has been conducting research into stereoscopic imaging topics for the past 20+ years. Over the past few years several third year physics students have worked on projects related to 3D displays and have revealed some very interesting results. Projects in this area would interest students with an interest in optics, displays, visualisation, and/or data analysis.
Improving the Spectral Quality of Inks for Low Crosstalk Printed 3D Images
A recent journal paper has identified that spectrally impure inks are a major source of crosstalk in printed anaglyph 3D images. The purpose of this project would be to perform optical measurements on a range of new ink types to find inks which offer better spectral performance for 3D purposes. The project will also involve some sleuthing to investigate whether some new technologies, such as quantum dots, might offer some opportunities for better ink spectral quality. A Matlab program is available which can be used to simulate the 3D performance of different inks types. The project may also offer the opportunity for the student to learn about colour management in printers as another way of improving 3D print quality. The mentioned journal paper found that there is considerable opportunity to improve 3D print quality we just need to test the proposed methods. There is prospect for a conference or journal paper to come out of this work.
Impact cratering is one of the most common geologic processes in the solar system. No surface in the Solar system has been spared. All surfaces preserve evidence of impacts, as a form of circular structures called craters. Understanding the effects impacts have on target rock is of great importance to the understanding of terrestrial and planetary geologic record, and with that the planetary evolution.
The Earth has experienced a lot of impact events in the past, however, being a geologically dynamic planet means that the evidence of impacts gets erased over time, faster than on other planetary bodies, like the Moon. Therefore, other methods are needed when conducting the search for impact evidence on Earth, because in most cases, there is no crater!
Impacts occur at large impact speed, delivering massive amounts of energies into the crust. The crust experiences significant shock pressures, substantial fragmentation and fracture as well as displacement. Impact energy partitions into the potential energy of the target (causing heating) and the kinetic energy of the ejecta (fragmentation and displacement). Specifics of shock physics occurring during cratering are not typical for any other geologic process. Therefore, by looking for shock evidence in target rocks, it is possible to uncover new impact structures on the Earth. This project will study effects of impact bombardment on a planetary surface and will classify degrees of shock deformation for a range of impact craters. Impact simulations will be made using a shock physics hydrocode. Furthermore, guidelines for estimating properties of suspected impacts on the Earth could be made.
Solar system has formed out of colliding dust and accumulated gas revolving around the young Sun. Planetesimals collided and aggregated into what we now know as planets, asteroids and other bodies. To understand the formation and evolution of planets a lot of efforts are being made to study their interiors.
NASA has recently selected a new space mission called Psyche to be launched in 2023, that will visit the 16 Psyche asteroid. This is a 200-km diameter asteroid that is thought to be an exposed iron-nickel core of a planetesimal. Visiting this asteroid will provide us with unique insights into metallic planetary cores and planetary differentiation, but also an insight into identifying resources from space.
The aim of this project is to investigate morphologies of impact craters on a material analogue to the 16 Psyche asteroid by making numerical impact simulations in a shock physics simulation software. The project involves studying the M-type asteroid compositions, materials analogue to the asteroid surfaces, and cross-referencing with known meteorites. It then studies the cratering process on such metallic materials under low gravity and low temperatures, environment typical of Psyche asteroid, to provide further insight into what this metallic world might be like.
Supervisor: Dr Katarina Miljkovic
Suitability: Honours, 3rd year
Mercury has the oldest confirmed magnetic field of any terrestrial world in the inner solar system. This has been surveyed in details by the NASA MESSENGER mission in the past decade. Its global magnetic field provided scientists with evidence Mercury still has a partially molten iron core, which acts as a dynamo to produce the magnetic field. However, the structure of the magnetic field at Mercury is quite complex. There are internal and external magnetic field contributions. The internal contributions are not only coming from the core, but from magnetised areas in the lithosphere. Some of these magnetic anomalies on Mercury could be associated with impact craters.
This project will contribute to the understanding of the magnetic structure of Mercury by looking at the contribution of exogenous material via impact bombardment. Numerical impact simulations will be used to estimate the delivery and survivability of asteroids that have been hitting Mercury during its evolutionary history.
Exploration of asteroids and small bodies in the Solar system is of great importance to learn more about the Solar system origins and evolution. However, soft landing on a small planetary body under very low gravity is an engineering challenge. Therefore, it is worth looking into alternative approaches. For example, sampling of the surface composition of a small planetary body without having to manoeuvre a soft landing could be done via dropping an impactor to cause ejection of the surface material and flying thought with another spacecraft to record or collect the ejected dust.
This project would look at dust ejection processes by an artificial impactor into an asteroid as well as the evolution of the expanding dust cloud, including the dust flux that an orbiter spacecraft could detect. Previous space missions using similar concepts include NASA’s missions Stardust that went to a comet and LCROSS that went to the Moon had similar concepts.
Half a century long exploration of Mars has revealed that there are large amounts of water ice in the polar regions, not only as part of the polar caps, but also in shallow subsurface, buried under a thin layer of dusty soil, called the regolith. These buried icy sheets can extent to lower latitudes, depending on the season.
Small meter-size craters form on Mars very frequently, and in the past decade there were potentially thousands of them. When these small craters form in the dusty polar/icy regions of Mars, they can excavate fresh water ice from underneath. However, that exposed ice immediately starts to sublimate. There is a large database of high-resolution orbital imagery of Mars, and there was a number of lucky shots when a freshly made crater was observed. This data can be used to further constrain the location and depth of this water ice layer.
This work is to produce series of meter-size crater formation simulations, using a hydrocode made for impact crater modelling, and investigate the necessary depth of the ice sheet as a function of crater size on Mars. The implication of this work is such that it contributes to knowledge of where to look for habitable resources on Mars.
Supervisors: Prof Victor Calo
Numerous phenomena from different areas of science and engineering are modelled by time-dependent partial differential equations. In general, it is impossible to find their analytical solutions. Thus, one seeks numerical approximations. In order to obtain accurate approximations, one requires to solve a large linear algebra matrix problem, which is time-consuming.
This project aims to develop fast solvers for the resulting linear algebra systems. The main idea is to perform directional splittings. We split a multiple dimensional problem into a series of one-dimensional problems. This significantly reduces the overall cost for solving the matrix problem to be of linear cost.
- Write numerical simulators to study the performance of the splitting schemes;
- Analyse the stability and approximability of the splitting;
- Generalise the splitting schemes to solve other time-dependent problems.
Supervisors: Prof Victor Calo
At the interface between two chemically active metamorphic minerals, a new phase grows and nucleates. In general, the reaction product is a rim, and its morphology depends on the large volumetric stresses associated with the chemical processes, i.e., mass transport and chemical reaction, as well as the curvature of the mineral interface.
By using a chemo-mechanical framework for the interactions of multicomponent solids, this project aims to identify the conditions under which the morphology of the rim varies from a uniform to a non-uniform layer.
Objectives: The primary goals of this project are to:
- Understand the impact of the diffusion coefficients, reaction rates and mechanical properties in the chemo-mechanical framework to perform relevant numerical simulations; and
- Postprocess simulation results to verify the rim growth-controlling mechanism.
Supervisors: Prof Victor Calo
We seek to develop an accurate and robust forecasting model of the temporal and spatial contagion distribution of COVID-19 within the community. We are extending state-of-the-art epidemiological models to allow us to establish risk-balance tables that will facilitate stakeholder decision making. We will model different policy scenarios to capture their impact on COVID-19 propagation and, more importantly, its impact on the health outcomes of the WA population. Once the model is validated and tuned to replicate COVID-19 propagation patterns, this simulator will allow decision-makers to assess how different policies may contribute to the propagation of COVID-19 within the community. Data from other regions may be necessary to model individual-to-individual contagion rates as well as recovery pace and deaths. These models will also seek to capture how public adherence to these policies will impact individual health outcomes as well as strains on the health system. This combination will allow the WA government to fine-tune the policies to minimize their impact on the population while maximizing the reduction of COVID cases.
The beta amyloid-amylin interaction: is there a molecular link between diabetes and Alzheimer’s disease? Biophysical and molecular simulation studies
Type-2 diabetes (T2D) is associated with an increased risk of dementia, including Alzheimer’s disease (AD). The molecular mechanisms behind this association are, however, not well understood. Both of these age-related, chronic diseases feature the accumulation of amyloid protein aggregates (beta amyloid or Aβ in the brain in AD and amylin in the pancreas in T2D). Recent studies at Curtin suggest that Aβ and amylin can co-exist in AD brain and synergistically interact to potentiate cell death and amyloid deposition. These findings suggest that amylin may cross-aggregate with Aβ, forming stable molecular complexes with increased toxicity. The direct interaction of these amyloid proteins is poorly understood, but could play a major role in the genesis and progression of pathological conditions in the brain and pancreas.
This project will offer the opportunity to use either biophysical or molecular dynamics simulation methods to study the interactions of Aβ and amylin and the structure of Aβ-amylin complexes. Surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC) determinations will be used to obtain direct measurements of the kinetics and affinity of binding between Aβ and amylin, as well as of their interactions as pre-formed oligomers with model cell membranes. Molecular dynamics simulations will be used to investigate the structure of the oligomers formed between Aβ and amylin in phospholipid bilayers as well as the changes induced in the structure and stability of these membranes. The outcomes of the project will shed much needed light into the cross-seeding mechanisms that underlie the pathological roles of these proteins in AD and T2D, which could be targeted with anti-aggregation drug molecules.
How does the crowded environment inside cells affect the translation of proteins?
The cell interior (cytoplasm) is highly packed due to the large amount of macromolecules (e.g. proteins, nucleic acids) as well as other biomolecules and ions present. The presence of these molecules alters the dielectric constant of the cytoplasm from that of dilute conditions. This phenomenon is commonly referred to as macromolecular crowding, and gives rise to an excluded volume effect, which effectively compresses proteins, reducing their average dimensions and favouring their native folded states. Importantly, it also affects the speed at which they can diffuse within the cytoplasm to reach and interact with other proteins.
In this project we will focus on how macromolecular crowding affects the rate at which transfer RNA (tRNA) molecules can reach the ribosome during the process of protein translation. In order to achieve this the cellular space will be treated as a three dimensional (3D) lattice and the motion of the tRNAs will be simulated using a random walk in discrete 3D space, allowing estimation of the time taken by tRNAs to reach the site of translation. The effect of macromolecular crowding on the dielectric constant further affects the magnitude of interactions between tRNAs and the ribosome at the site of translation, which is a necessary step in protein synthesis. In order to quantitatively understand this, binding affinities of different tRNAs to the ribosome will be calculated in both dilute and crowded conditions using molecular dynamics simulation models. The outcomes of this project will be used to estimate the rates of protein production and how they are affected by macromolecular crowding in the cell cytoplasm.
How do nanobiosensors detect proteins?
The mechanism of protein adsorption and ion transfer at the interface between two immiscible electrolyte organic/water solutions remains largely unknown. In particular, the complexation of charged molecules by proteins allows this adsorption process to be exploited to develop nanobiotechnological applications, such as biosensors that can detect proteins in very small concentrations.
This project will use molecular dynamics simulations to look at the way proteins interact at organic-water liquid interfaces in the presence of an electric field, their partial unfolding and aggregation that occur during this process, as well as the ability of hydrophobic anions to interact with these proteins and be transferred at different pH. Understanding these processes will be useful for optimising protein detection in nanobiosensors for the diagnosis and tracking of the effects of drug treatments.
Petritek is looking for students (contact Alec Duncan in the first instance).
Petritek have designed a new type of sensor for performing much more accurate measurements in industry. At the moment it outputs arbitrary units. We would like a student to come and work with us to fully characterize how those arbitrary units can be translated into useful data under different scenarios. We can manufacture all of the test rigs etc. as necessary.
This project aims correct for scatter and other blur artifacts by measuring a dynamic point spread function across the scan volume and then deconvolving that function from real images.
Medical Radiation Sciences
Supervisors: Dr Peter Fearns
Magnetic Resonance Imaging (MRI) uses differences in magnetisation relaxation times T1 and T2 to differentiate tissues and structures in patients. The Bloch equations describe the nuclear magnetisation as a function of time. Spatial data is formed through a series of electromagnetic excitation and read-out pulses. We would like to use a Bloch Simulator, Sycamore, to demonstrate basic pulse sequences then test the applicability of Sycamore for modelling Fast Low Angle Shot (FLASH) gradient echo sequences. Sycamore is python based with a C++ backend.