Current project abstracts

Astronomy and Astrophysics

Title: Accretion of planetary debris onto white dwarf stars

Supervisor: Dr Adela Kawka
Suitability: Honours, 3rd year

Description:
Many stars within our Galaxy host planets. Since the majority of stars end their lives as white dwarfs we want to know what happens to these planets once the star evolves and becomes a white dwarf. Up to now no planets have been found around white dwarfs however there is evidence that planets survive but as debris disks.

Elements heavier than helium are expected to sink and disappear below the atmosphere of a white dwarf, leaving either a pure hydrogen or helium atmosphere. However, a significant fraction of white dwarfs shows the presence of heavy elements such as calcium, magnesium and iron which means that they must have been accreted from circumstellar material. The discovery of polluted white dwarfs with large infrared excess suggests that this environment is a debris disk composed of asteroidal/planetary material.

The project will involve extracting, reducing and analysing mid- and high-resolution spectra of white dwarfs from the archives of the European Southern Observatory. These spectra will be fitted with model spectra to determine the white dwarf atmospheric properties such as the effective temperature, surface gravity and abundance of heavy elements. Finally, the measured abundance pattern will be used to determine the likely source of the accreted material.

Title: Advanced calibration and imaging with the MWA

Supervisors: Dr Natasha Hurley-Walker
Suitability: Honours

Description:
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. Its design has many small antennas rather than fewer larger antennas as is typical for radio telescopes working at higher frequencies.

Forming high-fidelity images with the MWA can be challenging. The issues include: the very wide field of view of the MWA, the large data volume due to having many antennas, the corrupting effect of the ionosphere, the unusual reception pattern of the antennas (they are fixed on the ground), among others. Processing MWA data can often violate assumptions inherent in conventional radio astronomy data processing software. More accurate techniques are available but often come at a huge computational cost. Because of this, supercomputers are required to process large quantities of MWA data.

This project aims to investigate and develop novel techniques in radio astronomy data processing to improve the performance and/or fidelity of calibration and imaging algorithms, with a focus on MWA and future SKA_Low data. The application of these techniques has the potential to impact the Epoch of Reionisation (EoR) and GLEAM survey science programs of the MWA, which have each collected several PB of raw data. These techniques will be vital for exploiting the full potential of the new long baselines of the MWA, installed in 2017.

This project is suited to a student with a strong interest in the fundamentals of radio astronomy and a solid background in computer science, maths and/or physics.

Title: Bright transient and variable radio sources from SKA prototype arrays

Supervisor: Assoc Prof Randall Wayth, Dr Jess Broderick, or Dr Marcin Sokolowski
Suitability: Summer or 3rd year project

Description:
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.

Title: Charmed, I’m sure – accounting for charm pion production and its effects on neutrino telescopes

Supervisor: Dr Clancy James
Suitability: Summer project, 3rd year, or Honours

Description:
This project will immerse you in the murky world of particle physics, and the murkier world at the bottom of the Mediterranean Sea. Neutrino telescopes such as ANTARES and KM3NeT analyse high-energy particles seen deep in the ocean to determine which were produced by neutrinos. Lies told to children state that only muon neutrinos undergoing charged current interactions produce the high-energy muons which reach the detectors from underneath. However, if a neutrino – any neutrino – produces a charmed meson (i.e. one containing a charm quark) as part of its (rare) interaction with matter, this can decay to produce a muon. This effect is not well accounted for in the simulations used to estimate detector sensitivity. This project will involve using computer simulations of high-energy neutrino interactions to investigate the production of charm mesons, their resulting decay processes, and their effects on the sensitivity of ANTARES and KM3NeT. It may also include an ANTARES/KM3NeT “shift”: the opportunity to remotely monitor/control the telescopes together with European collaborators.

Title: Characterising the ionosphere via scintillation measurements with the MWA

Supervisors: Dr John Morgan, Dr Chris Jordan
Suitability: 3rd year, Honours

Description:
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.

Title: Characterisation of radio-frequency interference at nanosecond timescales

Supervisors: Dr Marcin Sokolowski, Dr Clancy James
Suitability: 3rd year or summer project, expandable to Honours or Masters

Description:
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.

Title: Comparing diffuse cluster emission observed by both the MWA and LOFAR

Supervisors: Dr Amanda Wilber and Prof Melanie Johnston-Hollitt
Suitability: 3rd year, Honours

Description:
Clusters of galaxies are the largest gravitationally bound systems in the Universe, containing up to thousands of individual galaxies. Radio observations over the last several decades have revealed a population of large-scale diffuse structures associated with the intracluster medium (ICM) of many clusters. Radio halos and radio relics (with linear scales of about 3 million light years) are thought to be generated by cluster-wide turbulence and shocks that are induced by very energetic cluster-cluster mergers. In more recent years, radio telescopes have been designed and built to operate at lower frequencies so that astronomers can study a presumably even larger portion of the radio halo and radio relic population, not visible at higher radio frequencies. In this project, the student will compare survey data covering clusters that have been observed by both the Murchison Widefield Array (MWA) in Australia and the Low Frequency Array (LOFAR) in The Netherlands, starting with a region between +10 to +30 degrees in Declination. Mapping the brightness and morphology of these cluster radio sources will help to constrain the physical processes powering them.

Title: Detecting and Characterising the most compact objects in the Universe via higher-order moments

Supervisors: Dr John Morgan, Assoc Prof Jean-Pierre Macquart
Suitability: 3rd year, Honours

Description:
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.

Title: Detecting cosmic rays at the Murchison Widefield Array

(3 projects available)
Supervisors: Dr Clancy James, Professor Steven Tingay
Suitability: Honours, 3rd year, Summer

Description:
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).

Title: Determining the Connections Between Jets and the Accretion onto Supermassive Black Holes

Supervisors: Dr Nick Seymour, Dr Guillaume Drouart
Suitability: Honours, 3rd year, Summer

Description:
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.

Title: Did Galaxy Clusters Host more Radio Galaxies in the Past?

Supervisor: Prof Melanie Johnston-Hollitt
Suitability: Honours

Description:
Understanding the life cycles of radio galaxies and how environment influences that is one of the outstanding problems in Astrophysics. Recent observations with the Murchison Widefield Array (MWA) telescope have suggested that there were many more radio galaxies in the centre of galaxy cluster in earlier epochs in the Universe than at present. This is an intriguing and interesting idea, not only for understanding the life cycles of radio galaxies with supermassive black holes, but also as a potential solution to an outstanding question around why we see accelerated clouds of electrons in clusters, seemingly without a source. Could these old radio galaxy be the answer? In this project we will use data from the MWA and the Australian SKA Pathfinder (ASKAP) to search for evidence of a greater presence of radio galaxies in the centre of galaxy clusters in the past to see if we can address these outstanding questions.

Title: Extragalactic science from the Multifrequency Snapshot Sky Survey (MSSS)

Supervisors: Dr Jess Broderick, Dr George Heald (CASS)
Suitability: 3rd year, Summer

Description:
The Multifrequency Snapshot Sky Survey (MSSS; Heald et al. 2015, A&A, 582, A123) was the first northern sky survey carried out at low radio frequencies (below 250 MHz) with the Low-Frequency Array (LOFAR), a pan-European radio telescope with its core located in the Netherlands. With a competitive combination of bandwidth, sensitivity, and angular resolution, MSSS will facilitate novel science in areas such as supernova remnants and HII regions, nearby galaxies, pulsars, radio transients, and extended objects such as giant radio galaxies, clusters and relics. It will also have significant legacy value in the scientific literature: in combination with the GLEAM-X survey from the upgraded Murchison Widefield Array (MWA) in Australia, an all-sky, low-frequency catalogue at a resolution of an arcminute and better will be possible.

In anticipation of a first public data release, the MSSS team is conducting a variety of quality control checks on the data products. You will play an important role in these efforts by analysing a selection of large-area (200 square degrees), multi-band (119-158 MHz) mosaics that cover the entire northern sky. Not only will key metrics be assessed, but given that each mosaic is expected to contain up to 1000 radio sources, you will have the exciting opportunity to carry out scientific studies on a selection of interesting, and indeed sometimes unusual objects (e.g. Stewart et al. 2016, MNRAS, 456, 2321; Clarke et al. 2017, A&A, 601, A25; Chyzy et al. 2018, A&A, 619, A36). In this project, the science focus will be on extragalactic sources, such as, for example, the aforementioned giant radio galaxies, clusters and relics, as well as other potential topics such as high-redshift radio galaxies and compact steep-spectrum sources.

Title: Giant pulses from the Crab pulsar observed with the Giant Metrewave Radio Telescope

Supervisor: Dr Ramesh Bhat
Suitability: 3rd year

Description:
The young and energetic pulsar that resides in the 1000-year old Crab nebula is well known for its emission of giant radio pulses – extremely bright, short duration bursts that last for millionths of a second but outshine the nebular emission whenever they occur. While the physical processes giving rise to such sporadic emission remain elusive, the short durations of giant pulses make them extremely powerful probes of the small-scale structure and turbulence in the nebula’s interior. The delays and distortions caused by multipath propagation effects can be accurately measured and modeled to infer the nebular properties. The frequency band near 300 MHz (wavelength of ~1 metre) is one of the “sweet spots” for studying the brightest giant pulses from the Crab pulsar and such propagation effects, and coincidentally it is also the frequency band where the Giant Metrewave Radio Telescope (GMRT) provides its maximum sensitivity. This project will involve undertaking a detailed analysis of wide-band high-time resolution data obtained with the GMRT in the 300-500 MHz band for studying the nature of giant pulses and quantifying the evolution of their pulse structure with frequency, to characterise the nature of turbulence in the nebula’s interior and probe its small-scale (micro-arcsecond scale) filamentary structure.

Title: GPU simulations of MWA observations with WODEN

Supervisor: Dr Jack Line
Suitability: 3rd year project

Description:
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 a new 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, the bandpass frequency response, the primary beam shape of the MWA, and many more, depending on time. 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!)

Title: HI Absorption in High-redshift Radio Galaxies

Supervisors: Dr Natasha Hurley-Walker, Dr Nick Seymour, Dr Jess Broderick
Suitability: Honours

Description:
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”.

Title: Imaging twinkling radio sources

Supervisor: Dr John Morgan
Suitability: 3rd year, Honours

Description:
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.

Title: Investigating the Smallest Scales of Pulsar Magnetospheres Via Microbursts

Supervisors: Mr Sammy McSweeney & Ramesh Bhat
Suitability: 3rd year, Honours

Description:
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.

Title: Mathematical modelling of HII bubbles

Supervisors: Dr Mahavir Sharma, Assoc Prof Cathryn Trott
Suitability: 3rd year, Honours, Masters

Description:
At an age of approximately 400 thousand years, the Universe entered the `dark ages’ as the hydrogen recombined and became neutral. The dark ages came to an end when the first stars and galaxies formed that emitted the ionizing radiation that (re)ionized the hydrogen in the Universe. The neutral hydrogen emits via the hyperfine spin-flip transition, at 21cm wavelength, that provided a window into the history of the Universe through the dark ages and the epoch of reionization. A prime objective of the projects such as the Murchison Widefield Array (MWA) and of the upcoming Square Kilometer Array (SKA) is to detect and investigate the 21 cm signal (statistically).

Theoretically, it is of paramount importance to understand the nature of sources responsible for reionization and to model the progress of reionization. The ionized HII bubbles created by stellar populations in first galaxies expand as they are fueled by ionizing photons generated during the lifetime of stars, and the dynamics of their expansion can be worked out with radiative transfer equations. It is important to know whether an expanding HII bubble will break out of the galaxy or not. However, the brute force method that envisages detailed radiative transfer calculation for every galaxy in a simulation running at cosmological scales is computationally not feasible.

The idea is to develop remedies to bypass the brute force approach, and this project therefore will undertake the mathematical modelling of HII bubbles in galaxies. The stars act as sources and the already ionized gas has a tendency to recombine that acts as sink. The aim is to derive an efficacy factor, that is, how many photons per H atom are needed to ionize a galaxy. The project can be extended to investigate the implications for 21 cm power spectrum which is one of the main objectives of major radio telescopes (e.g. MWA, SKA).

Title: Monitoring low-frequency radio sky for transients

Supervisors: Dr Marcin Sokolowski, Dr Jess Broderick
Suitability: 3rd project, expandable to Honours or Masters

Description:
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.

Title: MWA all-sky monitoring

Supervisors: Dr Marcin Sokolowski, Dr Jess Broderick
Suitability: 3rd year

Description:
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.

Title: Neutrino astrophysics with KM3NeT

(2 projects available)

Supervisors: Dr Clancy James, Dr Ramesh Bhat, Dr Arash Bahramian
Suitability: Honours, 3rd year, Summer

Description:
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.

Honours project
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 ~thousand known blazars? This project (suitable for Honours level) would involve estimating the signature of neutrinos from photon-proton interactions in blazar jets that might be detectable by neutrino telescopes. It may also be possible to access historic x-ray data to search for evidence of these interactions.

Summer or 3rd-year project
A further possibility is: could pulsars produce neutrinos? The extremely strong magnetic fields of these rapidly rotating neutron stars are energetically capable of accelerating protons to the energies required for neutrino production. This project would involve correlating known pulsars with ANTARES data to test this hypothesis.

Title: New high-redshift radio galaxy candidates from GLEAM

Supervisor: Dr Jess Broderick, Dr Nick Seymour
Suitability: Honours, 3rd year, Summer

Description:
High-redshift radio galaxies (HzRGs; e.g. review by Miley & De Breuck 2008, A&ARv, 15, 67) are crucial beacons in the early Universe for exploring massive galaxy formation and evolution. Low-radio-frequency-selected samples have considerable potential in finding more of these rare objects (e.g. the recent discovery of the most distant radio galaxy known at z=5.72; Saxena et al. 2018, 480, 2733). Drouart et al. (in prep.) have developed a novel selection technique for efficiently finding HzRGs, making use of spectral curvature at low radio frequencies, along with a standard cut in near-infrared K-band magnitude. This approach has already resulted in the discovery of the second-most distant radio galaxy known, at z=5.55.

In this project, you will play an important role in extending the Drouart et al. study over much wider areas, and to radio flux density levels an order of magnitude fainter. In particular, you will make use of an updated catalogue from the Galactic and Extragalactic All-sky Murchison Widefield Array survey (MWA GLEAM Year 1 + Year 2; Franzen et al. in prep.), as well as near-infrared K-band data from the ESO VISTA Kilo-degree Infrared Galaxy survey (VIKING; Edge et al. 2013, The Messenger, 154, 32). The HzRG candidate selection process will be refined using both the above described data, as well as additional multi-wavelength data sets. Identifying radio galaxies above z > 6 (i.e. during the Epoch of Reionisation, when the Universe was less than one billion years old) would facilitate many exciting scientific opportunities.

Title: Probing the Astrophysics of Neutron Stars through Single-Pulse Polarimetry

Supervisors: Mr Sammy McSweeney & Ramesh Bhat
Suitability: 3rd year, Summer

Description:
Neutron stars are extremely compact, rapidly rotating objects 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 them (giving them the name “pulsars”) provides a window into the astrophysics of the relativistic plasma 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 data from the low-frequency Murchison Widefield Array telescope to investigate the polarisation characteristics of (individual pulses of) several bright, southern pulsars which have not yet been studied at such low frequencies. The successful completion of this project will result in an important contribution to the body of low-frequency observations of southern hemisphere pulsars, which is anticipated to result in a journal publication.

Title: Probing the Local Hot Bubble toward PSR B0950+08

Supervisor: Mr Sammy McSweeney & Ramesh Bhat
Suitability: 3rd year, Summer

Description:
The nearby and bright pulsar PSR B0950+08 has been extensively well-studied over the past several decades. It is amongst the most dynamic objects in terms of brightness variability on timescales of days and is one of the very few objects that has been studied for microstructure emission — temporal structure in pulsar’s radio emission on microsecond timescales. The relative proximity of this pulsar (located at a distance of about 300 parsecs) and its location in a direction where the low-density, X-ray emitting cavity that forms part of the Local Hot Bubble appears to have an elongated opening make it a well-suited target for low-frequency observational investigations using the Murchison Widefield Array (MWA). This will allow to revisit the claims of substantially lower plasma densities and turbulence strengths prevalent in the line of sight to this pulsar, signifying the coronal phase of the interstellar medium. In this project you will undertake high-resolution spectral analysis of the time-frequency structure of pulsar intensity modulation using some high-quality observational data obtained from the MWA in order to quantify the degree of turbulence in the pulsar’s line of sight and potentially determine the location of the underlying plasma screen. This will uniquely complement information obtainable using multi-wavelength investigations, thereby contributing to a growing body of evidence suggesting a somewhat atypical nature of the Solar neighbourhood.

Title: Rapid follow-up of high-energy flaring stars with the Murchison Widefield Array

Supervisors: Dr Gemma Anderson, Dr Paul Hancock
Suitability: Honours, 3rd year, Summer

Description:
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.

Title: Real-time detection of Fast Radio Bursts with the MWA

Supervisors: Dr Marcin Sokolowski, Assoc Prof Jean-Pierre Macquart
Suitability: 3rd year, expandable to Honours or Masters

Description:
Fast Radio Bursts (FRBs) are one of the most intriguing astrophysical phenomena discovered just over a decade ago. They are very short (order of miliseconds) 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.

Title: Real-time imaging of black hole jets

Supervisors: Assoc Prof James Miller-Jones
Suitability: 3rd year, Honours

Description:
We see a universal connection between inflow and outflow around astrophysical compact objects, such as black holes and neutron stars. When material (typically from a binary companion star) falls in towards a black hole, some of the liberated gravitational energy can be used to launch a powerful jet, which in some cases can move outwards at close to the speed of light. These can be imaged using high-angular resolution radio telescopes, which can resolve angular sizes comparable to a dollar coin in Sydney as seen from the vantage point of Perth. However, such telescope arrays are sparse, and observing strategies have typically required combining several hours’ worth of data. But for the fastest-moving jets, their motion can traverse the telescope’s resolution element in just a few minutes. We therefore require novel techniques to image these moving jets. In this project you will apply new techniques to try to image moving black hole jets in real time, providing accurate estimates of their physical parameters.

Title: Removing image artefacts from our nearest supermassive black hole

Supervisor: Dr Benjamin McKinley
Suitability: 3rd year project

Description:
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.

Title: Searching for bound supernova remnants

Supervisor: Dr Adela Kawka
Suitability: Summer project, 3rd year, or Honours

Description:
When a white dwarf explodes in a supernova, it may leave behind a bound remnant that is expelled with a large velocity. Supernovae that involve white dwarfs are classified as Type Ia supernovae. These cataclysmic events are standard candles used to measure cosmological distances and measure the age of the universe. We know that these types of supernovae are caused by the thermonuclear disruption of a white dwarf whose mass has reached the Chandrasekhar limit of 1.4 solar masses, the maximum mass of a white dwarf star. However, we know very little of the evolutionary paths leading to these explosions. A subclass of Type Ia supernovae are the subluminous Type Ia supernovae and these are predicted to leave behind a remnant of the exploding white dwarf. Only a handful of these remnants have been found.

The aim of this project will be to search for bound remnants and to study the properties of these stars. These surviving stars can be identified first by their peculiar Galactic motion and also their unusual physical characteristics, such a very low mass and an atmosphere without hydrogen or helium. As part of this project you will measure the stars’ motion through the Milky Way and retrace its past motion to identify the position of the supernova event. You will also analyse spectroscopic and/or photometric data to determine the bound remnants’ properties such as the temperature, mass and atmospheric composition.

This project will exploit the data from the orbital observatory Gaia that is measuring accurate positions, distances and velocities of over a 100 million stars in the Milky Way. The project will also involve spectroscopic surveys such as the Sloan Digital Sky Survey and archival observations obtained using the 4m to 8m optical telescopes of the European Southern Observatory (ESO) that is located in the Chilean Atacama desert and which provides the best observing conditions on Earth. These telescopes are equipped with state-of-the-art instruments covering a vast range of the electromagnetic spectrum from the near ultraviolet and optical to the infrared.

Title: Searching for Bright Radio-loud QSOs Near the Dawn of Time

Supervisors: Dr Nick Seymour, Dr Jess Broderick, Dr Luke Davies
Suitability: 3rd year, summer

Description:
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 SMNHs 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.

Title: Searching for Diffuse Radio Emission in Low Mass Systems

Supervisors: Prof Melanie Johnston-Hollitt
Suitability: Honours

Description:
In the hierarchical structure assembly of the universe matter is structured in galaxy groups, clusters and superclusters. It has long been known that galaxy clusters exhibit diffuse radio emission in the form of radio haloes and relics which are vast regions of radio emission associated with turbulence in the intracluster medium or cluster shocks, respectively. However there is an open question as to how massive a cluster must be in order to generate detectable diffuse radio emission, or indeed if galaxy groups, rather than clusters can also produce diffuse emission. Recent evidence suggests that both low mass galaxy clusters (less than 5 x 10^14 solar masses) and galaxy groups do have diffuse radio emission. This project designed to test such claims via use of data from the Murchison Widefield Array (MWA). The MWA is the world’s premier instrument for detecting radio haloes and relics in nearby systems. Using new and archival data you will determine the incidence of diffuse emission in low mass clusters and galaxy groups in the local (0.1 > z) universe. Using these results we will re-examine known radio halo scaling relations, potentially pushing them into the as yet unexplored region of parameter space for low mass systems. Results of this work should be publishable in a refereed journal.

Title: Searching for Spiral AGN

Supervisor: Prof Melanie Johnston-Hollitt
Suitability: Honours, 3rd year

Description:
Of all the millions of galaxies in the universe which host super massive black holes and emit large-scale radio jets, so-called Active Galactic Nuclei (AGN)< the vast majority of them are hosted by elliptical galaxies. However, there is a rare population of spiral and lenticular galaxies which have recently been uncovered which also host black holes of sufficient magnitude to emitted large-scale radio jets. So far only 16 just objects are known. In this project we will use data from the Murchison Widefield Array (MWA) and Australian SKA Pathfinder (ASKAP) radio telescopes, in conjunction with optical imaging from Pan-STARRs and other optical surveys to see if this population can be extended and then to see what common characteristics these rare objects have.

Title: Searching for the elusive pulsar in the supernova SN 1987A

Supervisors: Mr Sammy McSweeney & Ramesh Bhat
Suitability: 3rd year, Summer

Description:
The supernova SN1987A in our Galactic backyard (the Large Magellanic Cloud) has been an object of extensive research over the past decades. As is well known, this supernova produced a neutrino burst at the time of its explosion, signalling the birth of a neutron star. However, despite several intensive searches over the past three decades, a pulsar (another name for a rotating neutron star) has not yet been detected, which remains a mystery. Admittedly, the searches so far are unable to preclude the existence of a slowly-spinning pulsar (spin periods > 100 milliseconds) with modest surface magnetic field ($\sim10^{11-12}$ Gauss) and somewhat less energetic compared to most canonical pulsars. Moreover, the search efforts to date have all been carried out at frequencies above 400 MHz. The Murchison Widefield Array (MWA) thus presents a new parameter space to search for this elusive pulsar. Even with its modest sensitivity, a putative pulsar may be detectable, provided its radio spectrum is very steep (e.g. the Crab pulsar) and the pulsed emission is not subject to severe scattering at the low frequencies of the MWA. In this project you will process new observations made with the MWA to form a sensitive tied-array beam pointed toward the centre of this supernova and perform a systematic and thorough search for any likely pulsar candidate signals. The techniques will involve searching for both potential giant pulses (i.e. ultra-bright, short-duration bursts) as well as periodic emission. A positive result would undoubtedly mark a significant discovery and will offer the unique opportunity to study a pulsar at the beginning of its life, and will have several important implications for understanding pulsar birth periods, besides providing valuable insights into the origin and early evolution of pulsars produced by core-collapse supernovae.

Title: Searching for the origin of magnetic fields in white dwarf stars

Supervisors: Dr Adela Kawka
Suitability: Honours, 3rd year

Description:
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.

Title: Searching for transients and variables in the GaLactic and Extragalactic All-Sky MWA (GLEAM) survey

Supervisors: Dr Natasha Hurley-Walker, Dr Paul Hancock
Suitability: Honours

Description:
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. One of the largest science programs for the MWA is the GaLactic and Extragalactic All-sky MWA (GLEAM) survey, which has surveyed the entire visible sky for two years since the MWA commenced operations.

GLEAM has collected vast quantities of data. A large part of the first year of this data has been published as an extragalactic source catalogue. However, to produce this catalogue, all of the data was averaged together in time. The original data in full time resolution still remains to be investigated: hidden in these images are possible transient events, such as: flaring M-dwarf stars, reflective space junk, and potentially other undiscovered sources. There are also many astrophysical reasons for sources to change in brightness with time, such as scintillation from intervening plasma, and the flaring and dimming of distant black holes.

The project involves careful re-analysis of the original GLEAM data, using the combined catalogue as a reliable reference source. The student will search for objects which do not appear in the combined catalogue (transients), and identify their nature. There is also the potential to monitor the brightness of sources over time (variables). With approximately 7million source measurements to search and correlate, organisation and clear thinking are crucial skills.

This project would suit a student with good programming skills who is willing to learn more and search a large dataset for potentially interesting events.

Title: Shooting for the Moon – detecting ultra-high-energy cosmic rays with the Five hundred metre Aperture Spherical Telescope (FAST)

Supervisors: Dr Clancy James
Suitability: Honours

Description:
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 kilometer 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.

Title: Silicon monoxide masers towards evolved stars

Supervisors: Dr Chris Jordan
Suitability: Honours, 3rd year

Description:
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 wouldbe 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.

Title: Studying an odd stellar object on the edge of a star cluster

Supervisors: Dr Arash Bahramian and Assoc Prof James Miller-Jones
Suitability: 3rd year

Description:
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.

Title: Targeted searches for millisecond pulsars with the Murchison Widefield Array

Supervisors: Mr Sammy McSweeneyRamesh Bhat & Arash Bahramian
Suitability: 3rd year, Honours

Description:
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.

Title: Timing properties of X-ray binaries in star cluster 47 Tuc

Supervisors: Dr Arash Bahramian
Suitability: 3rd year

Description:
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.

Title: Transient and variable AGN from the ASKAP VAST survey

Supervisor: Dr Jess Broderick
Suitability: Honours, 3rd year

Description:
ASKAP, the Australian Square Kilometre Array (SKA) Pathfinder, has now started science operations. VAST, an ASKAP survey for variables and ‘slow’ transients (Murphy et al. 2013, PASA, 30, e006), will offer new insights into the dynamic radio sky at mid frequencies (~1 GHz). You will conduct some of the first ASKAP searches for variable and transient flaring activity – hallmarks of extreme physics (e.g. Pietka et al. 2015, MNRAS, 446, 3687) – from the active galactic nuclei (AGN) at the hearts of massive elliptical galaxies, as well as Seyfert galaxies. In particular, you will shed further light on the physical mechanisms responsible for (i) intrinsic variability in the central engines of powerful radio sources, and (ii) extrinsic variability due to refractive interstellar scintillation in our Galaxy. You will also investigate whether there are correlations between the variability statistics and other radio / multi-wavelength properties. Additionally, you will help to test and further develop the VAST transients pipeline, and determine how the results of this project can improve forecasts of the mid-frequency variable sky for future ASKAP studies, as well as investigations using the SKA.

Title: Understanding Fast Radio Bursts

(6 projects available)

Supervisors: Assoc Prof Jean-Pierre Macquart, Dr Ramesh Bhat, Dr Clancy James
Suitability: Honours

Description
Fast Radio Bursts (FRBs) are a newly-discovered population of millisecond-timescale transient events. Their origin is unknown, but they are thought to emanate at cosmological distances, making the observed emission from these events so luminous that their energetics pose a challenge to models of how radio emission could be produced. Only ~35 of these events have been detected since their discovery in 2007 and the acquisition of a larger sample of events will help us to understand the nature of these events.

The field is currently grappling with the most fundamental questions about these events:

  • What is their spectrum?
  • What is the brightness distribution?
  • Do FRBs represent one-off cataclysmic explosions, or do they repeat?
  • Only one FRB has currently been detected to repeat, despite intense campaigns to detect repetitions at the locations of other FRBs. Is this because repetitions are rare, or because the “repeating FRB” is a qualitatively different type of event to the other FRBs?
  • What are the progenitors of these events?
  • How distant are these events? Their distance distribution can disentangle their evolutionary history, a key component in finding the progenitors of these events.

CIRA is a key member of the CRAFT survey on the Australian SKA Pathfinder (ASKAP), which is currently detecting Fast Radio Bursts at a high rate, and which will soon be able to localise the bursts to 1” on the sky.

We are offering several projects in this field:

  1. Searching for repeating FRBs in ASKAP data
    Unlike previous FRB surveys, ASKAP constantly monitors the same patches of sky for FRBs. Hence, the region of sky in which any FRB is detected will have been observed many times. Here you will search the ASKAP data at the locations and dispersion measures of known FRBs to look for faint bursts by examining the statistical properties of the noise.
  2.  Searching for repeating FRBs with the Green Bank Telescope
    The Green Bank telescope is currently the world’s largest fully-steerable radio telescope. Here you will examine sensitive observations at the locations of known FRB events to look for exceedingly faint repeat bursts.
  3.  Parkes repetition data
    Here you will use data from the 64-m Parkes radiotelescope to search for repeat bursts from known FRBs.
    The detection of a repeating FRB from projects 1, 2 & 3 would enable us to use radio interferometers such as ATCA and the Very Large Array to localise the bursts to sub-arcsecond accuracy and hence determine exactly which galaxies the bursts come from.
  4.  Characterising the low-frequency spectrum of FRB emission
    No FRB has been detected below a frequency of ~600 MHz. Is this because no radiation is produced at low frequencies, or it is absorbed or scattered? Or has no-one simply detected it yet? Here you will examine time-domain data from the Murchison Widefield Array (MWA). A particular advantage of the MWA is that it has been undertaking “shadowing observations” of ASKAP, so that we know the times, locations and dispersion measures of events that should appear in the MWA data.
  5. What are the environments of FRBs?
    ASKAP has now begun localising FRBs to sub-arcsecond precision. Do they reside in the centres or outskirts of galaxies, and how do their properties relate to their immediate environment?
  6. Interpreting FRB dispersion measures
    The dispersion measures (DMs) of FRBs represent a means to probe the ionized Inter-Galactic Medium, the repository of over half of the Universe’s baryonic (normal) matter. But how do we interpret the DM? In this project you will investigate how the DM distribution depends on variations in the distribution of matter along individual sight-lights through the IGM.

Title: Using Machine Learning for Finding New Pulsars

Supervisors: Mr Sammy McSweeney & Ramesh Bhat
Suitability: 3rd year

Description:
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.

Title: Using the MWA to Detect and Monitor Near-Earth Objects

Supervisors: Dr Nick Seymour
Suitability: Honours, 3rd year

Description:
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.

Title: What happens when a black hole eats a star?

Supervisors: Assoc Prof James Miller-Jones, Dr Gemma Anderson
Suitability: 3rd year, Summer

Description:
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.

Applied Physics

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.

Find out more on RSSRG and learn more about the research voyage.

Net Community Production in the Eastern Indian Ocean

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.

Find out more on RSSRG and on Cassar Lab.

Dr Alec Duncan

Underwater acoustics

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.

Dr Christine Erbe

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.

Dr Iain Parnum

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.

Projects

  • Measuring and modelling of seafloor backscatter
  • Detection of marine gas seeps using acoustic techniques
  • Underwater acoustic monitoring of marine fauna

 Dr Andrew Woods

Stereoscopic imaging

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.

Ashley Barker (Petritek)

Petritek is looking for students for the following industry based projects (contact Alec Duncan in the first instance).

Project #1

Improvement of embedded software algorithms running onboard a microcontroller to improve spectrums being received. This is an optimization task, it will not actually require embedded C knowledge (but of course if the student wanted to actually code it themselves and learn C, that would be amazing). Once better spectrums can be achieved we would like to make some of these boards to measure around the surface of a volume. Then using the measurements from around the surface and the spectrum data it should be possible to do some maths to interpolate what the composition of the volume looked like and map out regions within the volume.

Project #2

We would like to look at performing a type of survey from drones. At the moment it is done by large aircraft, we would like to use drones to improve safety and quality of measurements. We will be using a different technique for mathematical processing of the data which will require building a mathematical model in matlab and if it can be proved then we would go and make the drone system hopefully as part of the project.

Project #3

This could potentially be done in cooperation with a large oil and gas operator. They have a particular asset that needs scanning with one of our products but it is not quite suited. So we would want to go through and mathematically model all of the different ways that the problem can be conquered. Again this would look like a matlab model.

Project #4

We 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.

Materials Physics

Dr William Rickard

Focussed Ion Beam – Scanning Electron Microscope (FIB-SEM) Project

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.

Dr David Saxey

Atom Probe Tomography

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.

Prof Charlie Ironside

FIB for Fab

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.

Dr Mark Aylmore and Kelly Merigot

TIMA Project

With the addition of our newest Field Emission Scanning Electron Microscope (FESEM), which is a Tescan Integrated Mineral Analyser (TIMA) fitted with four Energy Dispersive x-ray Spectroscopy (EDS) detectors. The TIMA is specialised towards high throughout mineral liberation analysis. Recent developments in EDS detectors and software have made fast chemical mapping possible. The TIMA uses x-rays to identify the elements that make up the sample being analysed and then compares the collected spectra to a phase database to produce a mineral distribution map. The composition can be determined quickly, though careful consideration must be made as to the sample preparation.

The parameters for EDS mapping have yet to be thoroughly investigated and verified. The project is designed to test the quality of results collected under various conditions and how the collection conditions control the outputs such as minimum grain size analysed. This project would involve an initial period of training to operate the microscope, followed by data collection and comparison of the results. The practical application of this project will be an improved methodology for mineral liberation analysis for all future users of this instrumentation.

Dr Irene Suarez-Martinez, Assoc Prof Nigel Marks

Benchmarking of Carbon Interatomic Potentials

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.

Dr Irene Suarez-Martinez, Assoc Prof Nigel Marks

New Carbon Phase with Mixed Hybridization

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.

Dr Matthew Rowles, Dr Irene Suarez-Martinez, Assoc Prof Nigel Marks

Simulating Diffraction Patterns of Graphitic Fragments

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.

Dr Irene Suarez-Martinez, Assoc Prof Nigel Marks

Giant Models of Glassy & Nanoporous Carbon

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.

Assoc Prof Nigel Marks

Noble Gas Release in Pre-Solar Nanodiamonds

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.

Dr Matthew Rowles

Materials by X-ray diffraction

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

Prof Craig Buckley, Dr Mark Paskevicius, Dr Terry Humphries, Dr Kasper Møller

Thermal Energy Storage Materials for Technological Application

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.

Dr Mark Paskevicius, Prof Craig Buckley

Next Generation Battery Materials

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.

Prof Craig Buckley, Dr Mark Paskevicius, Dr Terry Humphries

Metal hydrides for solid-state green hydrogen export

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.

Prof Craig Buckley, Dr Mark Paskevicius, Dr Terry Humphries

Evaluation of current thermal energy storage technologies

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.

Prof Craig Buckley, Dr Mark Paskevicius, Dr Terry Humphries, Dr Kasper Møller

Development of prototype thermal batteries

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.

Prof Ricardo Mancera

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.

Designing reconstituted high density lipoproteins as a cholesterol-lowering therapy in cardiovascular disease: a molecular dynamics simulation study

Low levels of cardioprotective high density lipoproteins (HDLs) are associated with cardiovascular disease. Reconstituted HDL (rHDL) therapy can improve atherosclerosis, and can also improve insulin levels in type-2 diabetes and possesses potent anti-inflammatory properties for the treatment of rheumatoid arthritis. Formulations of rHDL mimic the precursors of native HDL, which is the main HDL subclass that mediates the transport of so-called ‘good cholesterol’. Typical formulations involve phospholipid disks with apolipoprotein A-I (ApoA-I). Changes to the lipid composition of the formulation result in different-shaped rHDL particles and, importantly, changes to the conformation of ApoA-I, potentially affecting its ability to mediate the incorporation of cholesterol and its subsequent biochemical processing.
This project will apply molecular dynamics simulation approaches to characterise the self-assembly of rHDL particles of different lipid composition to investigate changes to their structure and, in particular, the structure of ApoA-I. The predicted properties of these rHDL particles will be used to rationalise their biological properties and therapeutic potential.

How does cryopreservation damage cell membranes?

Cryopreservation (the storage of cell and tissues at liquid nitrogen temperatures: -196°C) requires the use of so-called cryosolvents to promote the vitrification of water to minimize ice formation. Cryosolvents such as DMSO, glycerol and ethylene glycol can cross cell membranes, inducing vitrification inside cells. These agents, however, are toxic to cells and can indeed damage cell membranes themselves by changing their structure and functionality.

This project will use molecular dynamics simulations to predict the changes to the structure and stability of model cell membranes in the presence of aqueous solutions of different polyalcohols and sugar alcohols commonly used in cryosolvent mixtures, such as ribitol, xylitol, inositol, erythritol, mannitol and sorbitol. Elucidation of the mechanism of interaction of such poly-hydroxylated molecules with cell membranes will allow the future rational design of optimal multi-component aqueous mixtures of cryosolvents with improved cryopreservation properties. This will have applications in areas as diverse as the freezing of eggs and embryos and the preservation of germplasm from endangered plants.

How does the crowded environment in the cytoplasm affect the structure and stability of proteins?

The cell cytoplasm is highly packed due to the large amount of macromolecules (e.g. proteins, nucleic acids) as well as other biomolecules and ions present. 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. The effect of macromolecular crowding can thus affect significantly the biological function of proteins by modifying their conformations.
Molecular dynamics simulations will be used in this project to investigate the self-crowding of the regulatory protein calmodulin in an aqueous environment, and how it affects its native structure and thermal stability. The data generated will provide a molecular rationale for small angle neutron scattering (SANS) experiments being carried out by collaborators at the Australian Nuclear Science and Technology Organisation (ANSTO) in Sydney.

Understanding the mechanism of self-assembly of endocannabinoid-based lipid nanoassemblies for the delivery of drugs

Chronic inflammatory disease often leads to pain and dysfunction. Recently endocannabinoid-based lipid nanoassemblies have been developed as delivery vehicles for drug molecules. These systems have the advantage of being fully biocompatible due to the endogenous nature of the lipids used, and can be used for the controlled delivery of hydrophilic, hydrophobic and amphiphilic drug molecules.
Molecular dynamics simulations will be used in this project to characterise the mechanism of self-assembly of endocannabinoid-based lipids and their structure at different temperatures and levels of hydration. The outcomes of this study will facilitate the rational design of more effective nanoassemblies with optimal drug-carrying properties.

Dr Victor Calo

Reaction-induced stresses at mineral interfaces and its influence upon mineral morphology

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:
1) Understand the impact of the diffusion coefficients, reaction rates and mechanical properties in the chemo-mechanical framework to perform relevant numerical simulations; and
2) Postprocess simulation results to verify the rim growth-controlling mechanism.

Mathematical 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.

Prof Alisher Kadyrov and Prof Igor Bray

Physics of 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 depthdose simulations with a mm accuracy. The aim of the project is to develop a practical, efficient, and accurate theory of heavy ion collisions with biologically important molecules and provide a computer code for radiation dose calculations in hadron therapy of deepseated cancerous tumours.

Objectives:

  • Review the literature.
  • Learn how to use supercomputers to run locally developed codes.
  • Calculate stopping power for protons in soft and hard tissue.

Prof Alisher Kadyrov and Prof Igor Bray

Antihydrogen formation in antiproton collisions with rydberg positronium

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.

Objectives:

  • Review the literature.
  • Learn how to use supercomputers to run locally developed codes.
  • Calculate total cross sections for antihydrogen formation at low energies.

Prof Igor Bray and Prof Dmitry Fursa

Collision data for modelling of fusion plasma (ITER)

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.

Objectives:

  • 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.

Prof Igor Bray, Prof Dmitry Fursa and Prof Alisher Kadyrov

Positron collisions with atoms and molecules

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.

Objectives:

  • 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.

Dr Quanling Deng and Prof Victor Calo

Fast Solvers for time integrators

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.

Objectives:

  1. Write numerical simulators to study the performance of the splitting schemes;
  2. Analyse the stability and approximability of the splitting;
  3. Generalise the splitting schemes to solve other time-dependent problems.