# Third year and Honours projects

You should contact the supervisors of projects you are interested in and meet them to discuss their projects. Once you have decided on a project and have found a supervisor who is prepared to take you on, then email the name of your project and your project supervisor to the project coordinator, Alec Duncan. If you wish to do a project not included in the list, please contact a supervisor in your area of interest.

## Project units

• Physics Project 1 – Core for all streams, available in both semesters
• Physics Project 2 – Recommended elective for students with a CWA 65 or greater, available in both semesters
• The preferred option is to take PP1 in semester 1 and PP2 in semester 2 and combine them into a single year-long project.
• The choice of project may have a big influence on the direction of your career – so this is an important choice!

## Project Assessment

• End of semester report (40%)
• Supervisor’s assessment of your performance (40%)
• Oral presentation (PowerPoint or poster) (10%)
• Written summaries of seminars you have attended (10%)
• Fortnightly group meetings with supervisor (0%)

## Project Selection Process

By the end of the second week in December:

• Decide what projects you are interested in and go and talk to potential supervisors.
• Negotiate the details of the project and get an undertaking from the supervisor that they are prepared to take you on.
• Email Dr Alec Duncan with the title of your project, and the name of your supervisor
• Please note that students who delay choosing their project to the Orientation week or later cannot be guaranteed that a desired project or supervisor will be available.

## A Multiwavelength View of the Most Weakly Accreting Black Holes

Supervisors: Dr Richard Plotkin

Suitability: 3rd year

The Milky Way is likely littered with over hundreds of millions of ~10 solar-mass black holes, the remnants of the cores from the most massive stars after they explode as supernovae. Yet, observing these black holes is very difficult, and we have so far only identified several dozen.  One of the most common ways we infer the presence of a black hole is if it is located in an “X-ray binary” system, where material from the surface of a companion star flows toward the black hole through an accretion disk, thereby emitting large amounts of X-ray radiation. Some X-ray binaries also launch relativistic jets that emit primarily in the radio waveband. To connect the properties of the inflowing material to the outflowing jets requires a multiwavelength approach. In this third year project, the student will focus on an X-ray binary accreting at an extremely low accretion rate (at <10-8 of the Eddington limit).  The student will use data from ground- and space-based telescopes spanning the radio, near-infrared, optical, ultraviolet and X-ray.  By applying an accretion/jet model to the data, the student will explore the physical processes that determine how very low accretion rate systems emit radiation. Results from this project will provide crucial insight to help us learn how to isolate signatures from other weakly accreting black holes that might be lurking in our Galaxy, but that have so far eluded detection.

## Black-hole accretion in ‘radio-quiet’ quasars

Supervisors: Dr Sarah White

Suitability: 3rd year

The Square Kilometre Array (SKA) is a next-generation radio telescope that will allow us to detect sources with very faint radio emission. This includes ‘radio-quiet’ quasars (RQQs), which are supermassive black-holes that accrete material very efficiently. These black holes reside in host galaxies, whose star-formation processes are thought to be the origin of the quasars’ radio emission. However, black-hole accretion also produces radio emission, and recent work argues that this process actually dominates the emission in RQQs. In this project we will investigate the significance of this accretion component, in terms of its fraction of the total emission across all faint radio sources (i.e. normal star-forming galaxies, without an accreting black-hole at the centre, in addition to RQQs). This is crucial research, as it is currently expected that the total radio emission of such sources can be included in determining the star-formation history of the Universe. For this work, Python scripts are already in place but will require some editing before they can be run over a new, deeper radio image. A fairly straight-forward paper should result, with the student as a co-author.

## Catastrophic explosion or stellar shredder?

Supervisors: A/Prof James Miller-Jones

Suitability: 3rd year, Summer

When an unlucky star wanders too close to a supermassive black hole at the centre of a galaxy, the strong tidal forces of the black hole can rip the star apart, with the black hole then accreting some fraction of the stellar debris. The process of accretion leads to a luminous flare at optical and ultraviolet wavelengths, and the accretion can lead to the generation of relativistic jets.  However, with only a couple of dozen tidal disruption events studied to date, we do not yet understand the full range of behaviour shown by such exotic events, which can be confused with a rare class of stellar explosions known as superluminous supernovae.  One way to distinguish the two is via the radio emission that is expected to be generated by a tidal disruption event but not by a superluminous supernova.  In this project you will work on data from the Australia Telescope Compact Array radio telescope in New South Wales, stacking several epochs of data to place the deepest possible limits on the radio emission from this event, and hence constrain its true nature.

## Characterising the low-frequency spectrum of FRB emission

Supervisors: Dr Jean-Pierre Macquart, Dr Clancy James, Dr Ryan Shannon, Dr Ramesh Bhat

Suitability: 3rd year, Summer

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.  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.

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.

## Characterising the spectral features of ASKAP FRBs

Supervisors: Dr Jean-Pierre Macquart, Dr Clancy James, Dr Ryan Shannon, Dr Ramesh Bhat

Suitability: 3rd year, Summer

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.  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.

ASKAP FRBs show mottled structure across the band.  What does this mean?  Is this due to interstellar scintillation, or can you show that it is an intrinsic property of the FRB emission mechanism?

## Combining GLEAM and ATLBS to discover the history of active galactic nuclei

Supervisors: Dr Natasha Hurley-Walker, Dr Lakshmi Saripalli

Suitability: Honours, 3rd year

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.

Given the steep negative power-law spectra of synchrotron emission from radio galaxies, the low operational frequencies of the MWA are well-suited to detect and image relic lobes and hence past activity associated with active galactic nuclei. This project would use the GLEAM survey data in conjunction with higher-resolution imaging to construct a more complete picture of the activity history of AGN.

The exquisitely imaged and characterised sky region covered by the 1.4 GHz Australia Telescope Low Brightness Survey (ATLBS; Subrahmanyan et al. 2010; Saripalli et al, 2012) will be used for this exercise. In addition to the well-imaged and well-characterized information in the radio, the survey region also has available deep optical imaging and spectral data. Combining structural information from the high-resolution images of ATLBS radio sources with the well-separated low-frequency data from the GLEAM survey would render an effective method not only for discovering past activity phases of radio galaxies but also activity history as a function of source type. This project would suit an organised student interested in astrophysics and radio astronomy.

## Direct EoR Power Spectra: Bypassing the Curse of the Bins

Supervisors: Dr Steven Murray

Suitability: Honours

The detection of the Epoch of Reionisation (EoR), the period in which the first generation of stars and galaxies re-ionized the neutral hydrogen in the Universe, is one of the key science goals of the SKA and its precursor, the MWA. The primary quantity that is currently being pursued as the signal from this period is the 21cm power spectrum (PS) of fluctuations. Multiple methodologies have been developed in which to estimate this quantity from noisy data, given the specificities and peculiarities of the telescope that generates it.  Nevertheless, the majority of these methods suffer from the curse of binning; that is, individual baseline measurements are (incoherently) averaged in pre-defined square bins before being (coherently) averaged in pre-defined radial bins. Such a binning process is non-ideal, and may introduce subtle biases into the estimation. In this project, the student will utilise a general (integral) equation for the estimated PS, which theoretically does not involve any choice of bins. The student will develop a novel numerical method in which this theoretical equation may be efficiently realised. Such an implementation will be of enormous benefit in the quest for detecting one of the most exciting unobserved epochs in history.

## Do accreting white dwarfs produce jets?

Supervisors: A/Prof James Miller-Jones

Suitability: 3rd year, Summer

The process of accretion, whereby matter falls onto a central compact object, appears to be associated with jets throughout the Universe, from young stellar objects to neutron stars, stellar-mass black holes and active galactic nuclei.  We therefore expect that accreting white dwarfs should produce jets, but the evidence to date has not definitively proven that this is the case.  In this project, you will analyse radio observations from the e-MERLIN radio telescope in the UK, focussing on an outburst of the best-characterised white dwarf system known as SS Cygni.  This system is known to produce bright and highly variable radio emission during its regular outbursts, which occur every 45 days.  You will use the high resolution of the eMERLIN telescope to try to directly image the jets, as well as producing high time resolution radio light curves to study how the radio brightness changes with time, and how that correlates with the variable optical emission, which tracks the light emitted by the accretion flow. You will also look at the polarisation of the radio emission, in an attempt to determine whether the radio emission is synchrotron radiation from highly relativistic electrons in the jets launched by this fascinating system.

## Extreme spectrum radio sources in the GLEAM survey

Supervisors: Dr Paul Hancock, Dr Natasha Hurley-Walker

Suitability: Honours, 3rd year, Summer

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. The catalogues includes flux measurements at 20 different frequencies, however only sources that were seen at 200MHz were included in the catalogue. There exists a population of sources that have a very steep spectrum such that they can be detected at 70MHz but not at 200MHz. These sources are extremely interesting as they could potentially be either very old or very distant galaxies, or undiscovered pulsars.

This project will involve taking existing images from the GLEAM survey, subtracting all those that were already detected and analysing those that remain. The data and software that is required for this project has already been produced as part of the GLEAM survey but this search for steep spectrum radio sources has not yet been performed. This project will suit a student who would like to focus more on “the science” than the calibration and production of the data itself.

## Fast follow up of Gamma-Ray Bursts with the Murchison Widefield Array

Supervisors: Dr Gemma Anderson, Dr Paul Hancock

Suitability: Honours, 3rd year, Summer

Gamma-Ray Bursts occur either when a massive star undergoes core collapse or two neutron stars merge. In either case there is a short period in which a huge amount of material is accreted onto a newly formed black hole, and a very powerful jet of gamma-rays is launched  into space. For a small fraction of these events, the jet is aimed toward the Earth where it can be detected by gamma-ray satellites such as Fermi and Swift. 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 GRBs.

For the last 3 years, the MWA has been automatically responding to GRBs detected by the Fermi and Swift satellites, obtaining 30 minutes of observations following each outburst. There are now over 700 observations in the database that are being processed, and even more are being taken all the time. An automated pipeline is in place to download and process all these data and make the required images.

In this project you will analyse radio images to look for signs of prompt GRB radio emission – something that has never been seen before at radio frequencies. This project will help build your programming and time management skills, and will allow you to work on the Pawsey supercomputers.

## Finding the closest pulsar with the Murchison Widefield Array

Supervisors: Dr Ramesh Bhat

Suitability: 3rd year, Summer

Pulsars are nature’s premier laboratories for advancing extreme physics, including testing strong-field gravity and probing matter at nuclear densities. Numerous surveys over the past decades have led to the discovery of over 2500 pulsars, and a vast majority of them (>90%) are located at distances of the order of a few to several kilo parsecs. The integrated electron column density along the sight line from the Earth to the pulsar is called the “dispersion measure” (DM) and is a useful proxy for pulsar’s distance. Currently the closest pulsar known has a DM of 2.4 (in units of ${\rm pc\,cm^{-3}$) and an inferred distance of 130 parsecs. A candidate signal at an even lower DM has been detected in recent observations made with the Gauribidanur telescope that operates at very low frequencies. However, it is poorly localised on the sky along declination. The Murchison Wide-field Array (MWA) presents an ideal telescope for undertaking important confirmation and verification of this curious pulsar candidate. In this project you will undertake a systematic analysis of observations made with the MWA, spanning the highly elongated error box of the candidate signal. Data processing will involve forming a large number of sensitive pencil beams by re-processing raw voltage data and searching for periodic pulsations at the expected DM. If confirmed, this will be the closest pulsar ever known, with important implications for pulsar searches with both the MWA as well as the upcoming Square Kilometre Array (SKA) telescopes, besides serving as a powerful probe of the local interstellar medium, which is known to harbour multiple large super bubbles that were produced by a series of supernova explosions over the past few million years.

## Identification of flare stars for radio and optical observations

Supervisors: Dr Paul Hancock, Dr Gemma Anderson

Suitability: 3rd year, Summer

Variable stars offer a window into the life cycle of stars. Stars of all masses and of all ages exhibit some form of variability: from the seemingly gentle pulsations of Mira and Cepheids, to the blinking of binary stars during transit, to explosive novae that eject material from the surface of a star, end eventually to supernovae that mark the end of a star’s life and their rebirth as a neutron star or black hole. This project will monitor a large number of known variable stars using the Murchison Widefield Array (MWA) and the AstroSmall camera both described below.

The MWA is a low frequency (80-300 MHz) radio telescope operating in Western Australia and the only SKA_Low precursor telescope. The MWA has been in operation for over 5 years and has collected many petabytes of data. The MWA is currently being upgraded to have longer baselines that will increase the spatial resolution and allow for a more detailed study of compact objects such as stars within our Galaxy.

The Desert Fireball Network (DFN) has deployed some 50 DSLR cameras in remote locations around Western and South Australia. These cameras operate autonomously and capture images of the night sky every 15 seconds, with the aim of detecting fireballs and recovering the fallen rocks. One of the DFN cameras has been modified for use as an astronomical sky monitor, searching for flare stars, novae, eclipsing binaries, and as-yet undiscovered bright transient events. This camera, AstroSmall, has been in operation for 2 years and has collected many terabytes of data.

The goal of this project is to generate a list of known variable stars that may have been observed with the MWA and AstroSmall by  drawing from the large amount of existing knowledge present in databases, catalogues, and papers already available on the internet. With time permitting, it will be possible to analyse existing optical and radio data for a subset of these stars.

## Identifying optical counterparts of radio sources using citizen science

Supervisors: Dr Natasha Hurley-Walker, Dr Sarah White, Dr Nick Seymour

Suitability: Honours

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. These data have relatively low resolution, about 1/30th of a degree; optical data has about 1000x better resolution, so there is some difficulty in identifying exactly which galaxy is emitting radio waves.

TAIPAN is a multi-object spectroscopic galaxy survey starting in late 2017 that will cover the whole southern sky and will obtain spectra for over one million galaxies in the local Universe (z<0.3) over 4 years. This will be the most comprehensive spectroscopic survey of the southern hemisphere ever undertaken. The Taipan galaxy survey will use the refurbished 1.2m UK Schmidt Telescope at Siding Spring Observatory with the new TAIPAN instrument which includes an innovative starbugs optical fibre positioner and a purpose-built spectrograph.

Matching radio sources to optical counterparts is key to understanding the radio population. Optical observations can provide redshifts and reveal crucial properties of the host galaxy, e.g. stellar mass and star formation rate. One useful route is to use higher-resolution, higher-frequency radio catalogues to “bootstrap” from the low-frequency, low-resolution image, up to a better cross-match, but there is still a 100-fold difference in resolution between the optical and the radio. The Radio Galaxy Zoo project (https://radio.galaxyzoo.org/) aims to bridge the gap between infrared and radio observations. We would like to expand this approach to connect the recently-completed GLEAM survey, and the upcoming TAIPAN survey.

The project would involve building on existing cross-matching tools to automate the bootstrap as much as possible, and then working with experienced astronomers to figure out the true matches more difficult cases. Then, these skills need to be transferred to a web-based tutorial in the Radio Galaxy Zoo framework, teaching citizens how to perform the cross-match themselves. Finally, the GLEAM and TAIPAN datasets would be rolled out in the framework, and the project opened to the world to test out.

This project would suit a student interested in outreach and citizen science, with good problem-solving skills. Programming experience would be helpful.

## Investigating the Dispersion Measure Distribution of FRBs

Supervisors: Dr Jean-Pierre Macquart, Dr Clancy James, Dr Ryan Shannon, Dr Ramesh Bhat

Suitability: 3rd year, Summer

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.  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.

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.

## Measuring the Evolution of Powerful Radio Sources Across Cosmic Time

Supervisors: Dr Nick Seymour

Suitability: 3rd year

Radio surveys are superb tools to trace powerful star forming galaxies and the host galaxies of supermassive black holes across cosmic time. This project will utilise early data from state-of-the-art surveys with Australia’s impressive suite of world class radio facilities: the Murchison Widefield Array, the Australian Square Kilometre Array Pathfinder and the Australian Telescope Compact Array. These telescopes are all conducting deep surveys of the GAMA23 region of the sky (http://www.gama-survey.org/) over a wide range of frequencies (70MHz to 10GHz). When combined this broadband radio data will allow us to characterise the physical origin of the radio emission. The multi-wavelength optical data from GAMA will be used to identify the host galaxy and to determine it’s redshift. With the thousands of radio sources in our sample we shall be able to provide one of the best measurements of the evolution of radio sources across cosmic time.

## Observational Strategy for the Square Kilometre Array EoR Experiment

Supervisors: Dr Cathryn Trott

Suitability: Honours

The Epoch of Reionisation experiment is one of the science drivers for the Square Kilometre Array (SKA). We aim to detect and measure the emission from neutral hydrogen in the first billion years of the Universe, as a tracer of the formation of the first stars and galaxies. The EoR program with the SKA takes a three-tiered approach whereby shallow/medium/deep surveys aim to explore different components of the signal. This project will take a census of the currently-known low-frequency radio sky and help to shape the observing fields for these tiered experiments. The first part of the project will define metrics for assessing the quality of a given observing field. The second will cross-match these with known sky properties to help define the observing fields for this key experiment.

## Parkes repetition data

Supervisors: Dr Jean-Pierre Macquart, Dr Clancy James, Dr Ryan Shannon, Dr Ramesh Bhat

Suitability: 3rd year, Summer

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.  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.

Here you will use data from the 64-m Parkes radio telescope to search for repeat bursts from known FRBs.  The detection of a repeating FRB 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.

## Probing the Local Hot Bubble using low-frequency pulsar measurements

Supervisors: Dr Ramesh Bhat

Suitability: 3rd year, Summer

Pulsars make excellent tools to study the interstellar medium (ISM) of our Galaxy. Their radiation is beamed and polarised, and appear to an observer on the Earth as pulsed and dispersed. The compactness of pulsars make them ideal point sources, and as a result their signals are subject to a rich variety of propagation phenomena as they make their way through the interstellar medium to reach us. These properties make pulsars unique probes of the intervening interstellar plasma, especially its density structure and turbulence at very small scales. The most notable ISM effects are scintillation (i.e. the radio analogue of twinkling) and pulse broadening (lengthening of the pulse profile), both arising from multi-path propagation through the ISM, and are most pronounced at the low frequency bands in which the Murchison Widefield Array (MWA) operates (from ~80 to ~300 MHz).  Pulsars located within a few kilo parsecs of the Sun are of particular interest as their scintillation and dispersion properties will be substantially influenced by the material in and around prominent local features such as the Local Bubble and its nearest neighbour, the Loop I (also known as the North Polar Spur). Observations at X-ray and EUV bands also point to the evidence for an interaction zone between these two bubbles, which can be best studied using nearby pulsars in the southern hemisphere. In this project you will make use of an increasing number of low-frequency pulsar measurements that are emerging from the MWA as well as published measurements from the literature to revisit (and refine) our current model for the Local Interstellar Medium; specifically the distribution of turbulent plasma in and around the Local Bubble and Loop I. Findings from this investigation will be of great interest to both pulsar and ISM researchers, besides yielding a better understanding of our own local interstellar environment.

## Probing the Milky Way’s invisible gas via interstellar scintillation

Supervisors: Dr Paul Hancock, Dr Gemma Anderson

Suitability: Honours, 3rd year, Summer

The gas between the stars (interstellar medium or ISM) accounts for around 15% of the total mass in the disk of the Milky Way, but with a density that is so low that it is difficult to observe directly. Some of the ISM is either hot or dense enough that we can observe it directly but for the most part, the ISM is invisible. When the ISM becomes ionised, the free electrons can disturb our view of background galaxies by focusing and defocusing the light and causing a scintillation analogous to the twinkling of stars that we can see with the naked eye at night.

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. We have conducted a survey with the MWA that repeatedly imaged thousands of galaxies. With a carefully calibrated set of images, we can then look for sources that are scintillating, which will in turn allow us to map the turbulence within the interstellar medium. We have developed a theoretical model that will predict the distribution of turbulence, and are now looking to test this model with real data.

This project will involve taking a set of already created images, performing some quality assurance tests, and then creating catalogues of sources, and searching for variability. This project will involve working with python code on linux based systems, including supercomputers and cloud based machines at the Pawsey supercomputing facility.

## Radio Recombination lines with the MWA

Supervisors: Dr Natasha Hurley-Walker, Chenoa Tremblay

Suitability: Honours

Radio recombination lines (RRL) are produced when atoms cascade into a series of successively lower ionisation states.  In particular, the RRLs found at low frequencies are highly sensitive probes of the environment where the atoms are found, making them useful diagnostics of temperature, density and pressure.

RRLs at low frequencies were first discovered in 1980 and have since been discovered at frequencies from 14 to 1420MHz.  However, the region between 100 — 200MHz is not well studied.  Early studies suggest that somewhere between 100 and 200MHz the RRLs transition from emission lines to absorption lines. Recent constraints from studies by LOFAR have suggested that this transition may be around 130MHz.

This project will utilize data cubes generated and published by Tremblay et al (MNRAS submitted) as part of a spectral line survey with the Murchison Widefield Array (MWA) to search for RRLs, with a particular focus on carbon recombination lines from 103 to 133MHz.

In 2017 the MWA received upgrades to increase its resolution, so new data taken in this mode may also be used to search for lines, adopting existing spectral line pipelines. This project is suited to a student with a strong grounding in astrophysics and a good understanding or willingness to learn statistics so that these sensitive measurements may be made in a robust and quantitative way.

## Searching for gravitationally lensed high redshift galaxies in the TAIPAN survey

Supervisors: A/Prof Randall Wayth, Prof Simon Driver (UWA)

Suitability: Honours

How do you weigh a galaxy? There are a few ways to tackle this question. One of them is to use the phenomenon of gravitational lensing, whereby the light from a distant background galaxy is bent and warped by the gravitational field of another galaxy along the line-of-sight. The amount of observed light bending provides a direct measure of the mass of the intervening galaxy, hence gravitational lens systems are highly valuable astrophysical probes. This project will search for new gravitational lens systems using the new TAIPAN spectroscopic survey by analysing the observed spectra for signatures of lensing systems.

## Searching for repeating FRBs in ASKAP data

Supervisors: Dr Jean-Pierre Macquart, Dr Clancy James, Dr Ryan Shannon, Dr Ramesh Bhat

Suitability: 3rd year, Summer

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.  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.

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.

## Searching for repeating FRBs with the Green Bank Telescope

Supervisors: Dr Jean-Pierre Macquart, Dr Clancy James, Dr Ryan Shannon, Dr Ramesh Bhat

Suitability: 3rd year, Summer

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.  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.

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.  The detection of a repeating FRB 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.

## Searching for the elusive pulsar in the supernova SN 1987A

Supervisors: Dr Ramesh Bhat

Suitability: 3rd year, Summer

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 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.

## Searching for the needle in a haystack: a way to identify FRII radio galaxies in the radio Universe

Supervisors: Dr Guillaume Drouart

Suitability: Honours, 3rd year, Summer

Accreting supermassive black hole in the centre of galaxies produces powerful radio jets visible at radio frequencies. Recently, for the most powerful type (so-called FRII-class objects), a new technique demonstrated the possibility to use these sources as cosmological candles, using their size as a distance indicator. This work was performed only on well known sample and only within the uppermost part of the radio luminosity function. The next step is to find a new way to identify these sources (i) in higher number across the sky and (ii) at a lower luminosity regime. While having very interesting outcomes from a cosmological point of view and as a new tool to provide redshift measurement in a complete independent way from other frequencies, the exploration on new radio survey is yet to be done. The association of the spectral coverage of the GLEAM survey (70-230MHz, 2arcmin resolution) in combination with the resolution of the TGSS survey (150MHz, 25arcsec resolution) offers a unique chance to answer this question. The project will focus on identifying sources in GLEAM which break into multiple components at higher resolution and investigate the effect on the spectral index of these sources as well as their size distribution.

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

Supervisors: Dr Paul Hancock, Dr Natasha Hurley-Walker

Suitability: Honours

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.

## Silicon monoxide masers towards evolved stars

Supervisors: Dr Chris Jordan, Dr Rajan Chhetri

Suitability: 3rd year

Asymptotic giant branch stars and red super-giant stars are common sources to power silicon monoxide (SiO) masers. Masers can be thought of as radio-wavelength lasers, and are powered by energetic and exotic conditions in space. In this study, the SiO masers are powered by in-falling and out-flowing motions of gas surrounding an evolved star. As not much is known about these masers, this project presents an opportunity to advance the “big picture” science of evolved stars. 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 between the different spectral lines will be an important contribution to the understanding of evolved stars. In extremely rare cases, SiO masers can be excited by star-forming regions. A detection of this kind would be very important, warranting further investigations.  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.

## Simulating the reflected radio signal from the Moon

Supervisors: Dr Ben McKinley

Suitability: Honours

Did you know that the Moon can potentially be used as a reference source in the sky in a way that will allow us to measure the effects of the first stars, galaxies and black holes that formed in the Universe?! True story. One outstanding problem is that we need to understand what the Moon looks like at radio frequencies in great detail and this is complicated by the fact that it reflects radio waves from both the Earth and from the bright plane of the Milky Way. This project will involve simulating the reflected radio signal from the Moon, using ray-tracing techniques similar to those used in video game programming to render light and shadows on surfaces and backgrounds. The results will be used directly in the analysis of data from the experiment with the Murchison Widefield Array telescope that is currently underway. Fame, fortune and Nobel prizes await those who dare to attempt to understand the radio properties of our nearest neighbouring celestial body!

## Statistical Simulations of Extended Sources for the EoR

Supervisors: Dr Steven Murray

Suitability: Honours

The detection of the Epoch of Reionisation (EoR), the period in which the first generation of stars and galaxies re-ionized the neutral hydrogen in the Universe, is one of the key science goals of the SKA and its precursor, the MWA. However, such a detection is overwhelmingly difficult, as the signal lies behind a gamut of obscuring foregrounds — both other galaxies and our own galaxy, along with instrumental noise. The path to detection thus requires a precise statistical model of these “foreground” sources. Nevertheless, such models are hard to come by, and typically we are constrained to use simplistic approximations, for example approximating all extra-galactic sources as ideal points. In this project, the student will devise and build an efficient code to generate statistically consistent extra-galactic source simulations which also contain extended sources. There will be a focus on algorithmic efficiency, as these simulations will be required en masse, to produce numerically-calibrated covariance matrices for EoR signal extraction.

## The search for flaring and exploding stars using an autonomous camera deployed in the WA desert

Supervisors: Dr Paul Hancock

Suitability: Honours, 3rd year, Summer

Variable stars offer a window into the life cycle of stars. Stars of all masses and of all ages exhibit some form of variability: from the seemingly gentle pulsations of Mira and Cepheids, to the blinking of binary stars during transit, to explosive novae that eject material from the surface of a star, end eventually to supernovae that mark the end of a star’s life and their rebirth as a neutron star or black hole. To study variability there are two main approaches: a very deep and sensitive survey of a small patch of sky, or a less sensitive but much more inclusive study of a large area of sky. The advantage of a large area, low sensitivity survey is that it doesn’t require an enormous and expensive telescope, just a lot of images from a consumer grade camera.

The Desert Fireball Network (DFN) has deployed some 50 DSLR cameras in remote locations around Western and South Australia. These cameras operate autonomously and capture images of the night sky every 15 seconds, with the aim of detecting fireballs and recovering the fallen rocks. One of the DFN cameras has been modified for use as an astronomical sky monitor, searching for flare stars, novae, eclipsing binaries, and as-yet undiscovered bright transient events. This camera, AstroSmall, has been in operation for 2 years and has collected many terabytes of data.

Over the last year we have developed a calibration method that allows us to measure precise and accurate star positions and magnitudes. This project will require the use of the Pawsey supercomputing facility to calibrate many months worth of images, and make extensive light curves for tens of thousands of stars. The goal is to conduct a blind search for the most variable, and most interesting stars so that we can study them in detail. Some of these transient events will have simultaneous radio observations with the Murchison Widefield Array, which will give us an even better understanding of the events. This project is suited to a student that wants to improve their computing and programming skills, and who wants to learn about the many types of variables stars.

## The variability of jets from weakly accreting black holes

Supervisors: Dr Richard Plotkin

Suitability: 3rd year

Every large galaxy hosts a supermassive black hole at its centre, including our own galaxy the Milky Way which contains a 4 million Solar mass black hole called Sgr A*. The vast majority of black holes accrete material at very low rates, in a regime where it appears commonplace to launch jets of material that move away from the black hole at relativistic speeds. These jets emit radiation predominately at radio frequencies.  While there is strong evidence supporting the existence of jets at low accretion rates, the level to which the jet properties vary with time are not well constrained. In this project, the student will examine the variability of the jet launched by one of the smallest (~10 Msun) and closest (~1 kpc) known black holes, which is accreting very weakly and serves as a low-mass “cousin” to the supermassive black hole Sgr A*.  Using ~two dozen radio observations taken every 1-2 weeks from the Very Large Array radio telescope, the student will quantify the flux variability from this black hole.   From these results, the student will investigate how steady the jet may or may not be over time.  The student will place constraints on the level that variability must be accounted for in theoretical models of jet physics (which typically assume a steady jet), and also determine if neglecting radio variability affects our ability to use radio jet emission to identify new populations of stellar and supermassive black holes.

## “The A-Team”: Low-frequency Observations of the Brightest Radio Galaxies in the Southern Sky

Supervisors: Dr Natasha Hurley-Walker, Dr Sarah White

Suitability: Honours

The Murchison Widefield Array (MWA) is a low frequency (80 — 300 MHz) radio telescope operating in Western Australia; its location in the southern hemisphere gives it an excellent view of the Galactic Plane, and several bright radio galaxies: Hercules A, Fornax A, Virgo A, Hydra A, Centaurus A, and Pictor A: colloquially and collectively called “The A-Team”.

These radio galaxies are some of the closest and brightest objects visible with the telescope, but are so bright that they are often removed or “peeled” from observations without being well-characterised, in order to reveal fainter sources. However, these objects are interesting, because they are powerful, bright, and close enough that even with the MWA, relatively fine details can be observed. At low frequencies, this can give insights into the nature of the jets emitting from the central black hole; for instance, it is suspected that the jets of Pictor A become partially synchrotron self-absorbed, causing the spectrum to flatten at low frequencies.

This project aims to use the best observations from many hundreds of hours of observations of these very bright sources to completely characterise them over the entire MWA band, as well as new high-resolution observations from the extended MWA and the GMRT to explore their complex morphologies at low frequencies. The resulting sky models will be extremely useful for calibration and peeling for the rest of the international MWA team, and also for future work with the Square Kilometre Array. Insights into the astrophysics of the individual sources may well result in papers in refereed journals.

This project is suited to a student with a strong grounding in astrophysics and a willing to learn various software data reduction packages in order to create the best images possible.

## When is a pulsar not a pulsar?

Supervisors: A/Prof James Miller-Jones

Suitability: 3rd year, Summer

A new class of pulsars has recently been discovered, that switch between behaving as a rotation-powered pulsar and an accretion-powered X-ray binary.  This discovery vindicates our picture of how millisecond pulsars are created, whereby old pulsars that have slowed down and moved beyond the pulsar “death line” (where pulsations cease) are spun up by accretion from a binary companion to create a rapidly-spinning millisecond pulsar. They provide excellent laboratories for studying the accretion process in strong magnetic fields.  To date, only three such systems are known, which show bright gamma-ray and radio emission when in their accreting state.  In this project you will process observations from the Australia Telescope Compact Array radio telescope, aiming to find new transitional millisecond pulsar candidates in a radio survey of unidentified gamma-ray emitting sources, and analysing pointed observations of previously-identified candidates to ascertain their nature.

## 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 is having in situ data. 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/)

Two of the proposed projects provide examples of questions that could be tackled with the use of satellite remote sensing and the BOUSSOLE time series during a 3rd year project.

### Validation of satellite observations off Rottnest Island, Perth

The RSSRG has got an ARC funding to deploy a profiling mooring off Rottnest Island, Perth. This new equipment will collect vertical profiles several times a day of optical and biological properties of waters at that site. The data set will allow 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) onboard the Sentinel-3 satellite. The work will consist in processing the profiling mooring data set, assembling them with 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.

### Anomalies of optical properties in the Mediterranean Sea

Optical properties of oceanic waters are determined by seawater itself and by any particulate or dissolved substance that has an impact on either light absorption or scattering or both. Changes in these optical properties explain why the colour of oceanic waters varies from deep blue (open ocean, low phytoplankton content) to various tones of green (closer to the coast, with increasing levels of phytoplankton), and to brown when sediments are suspended into the upper layers. The domain of understanding how ocean optical properties are related to the presence of particles and dissolved substances of biological origin is called bio-optics. Interpretation of satellite ocean colour observations is based on so-called bio-optical algorithms. Average relationships have been established at the scale of the global ocean, for instance between the ocean spectral reflectance and the concentration of chlorophyll, which is a pigment present in all phytoplankton species. Local deviations from such global relationships exist, however, and lead to misinterpretation of the satellite signals. Here we propose to quantify such “anomalies” from a >10 years time series of optical measurements performed at a fixed site in the Mediterranean Sea (the “BOUSSOLE” time series), and possibly to identify their causes.

### 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 and primary productivity off WA through the use of NASA satellite ocean colour remote sensing products and a model of phytoplankton photosynthesis. Archives of such products date back to 1998 and, therefore, allow studying seasonal, inter-annual and decadal changes.

### Ocean properties along the Antarctic circumpolar Expedition

An international expedition is currently under preparation, which will navigate around the Southern Ocean during 3 months (Dec 2016-March 2017). It is called the “Antarctic Circumpolar Expedition”. In partnership with many international collaborators including NASA scientists, we plan to equip the ship with optical instrumentation in view of better understanding these properties in this under-sampled ocean, and to use the data to validate what the satellites see there. In preparation for this expedition, it is proposed here to evaluate the type of oceanic waters that the expedition might encounter, based on predicted trajectories of the ship, and on satellite observations of parameters such as the sea-surface temperature and the phytoplankton biomass.

### Non-meteorological use of the Japanese Geostationary sensor “Himawarii-8”

The Japanese Space and Meteorological Agencies have recently launched a geostationary satellite that takes observations of the Earth disk including Australia every 10 minutes. It is called “Himawarii-8”.  Although this mission primarily aims at meteorological applications, the characteristics of the sensor likely allow the determination of some ocean properties, such as the sediment concentration in large river plumes or dredging plumes. The high frequency of observations allows processes to be much better observed as compared to what can be done with more classical orbiting sensors. Here we propose to explore this possibility, using available Himawarii data, and bio-optical models developed in our group. The work will include comparison with NASA sensors that form a reference to which this new Japanese sensor can be evaluated.

## Dr Peter Fearns

Dr. Peter Fearns specializes in remote sensing methods to monitor the Earth’s environment. Recent projects have included airborne hyperspectral surveys of Ningaloo and Shark Bay, collaboration with NASA to map the Great Barrier Reef, monitoring toxic algae in the Swan River using a boat-based sensor, and mapping Marri tree flowering to support the honey industry using a drone!

Projects usually require students to have some computer programming capability and sometimes an ability to deploy instruments in the field.

### Monitoring reef water quality off the coast of Miri

Researchers at the Curtin Miri campus in Indonesia are keen to collaborate with us to map turbid river outflows that impact the coastal reef systems. This project will build on work already undertaken in the WAMSI Dredge Science Node which developed advanced methods to monitor turbid dredge plumes using MODIS, Landsat and WorldView-2 sensors.

### Testing a low power laser for bathymetry mapping

Bathymetric mapping in shallow coastal waters can be efficiently carried out using airborne LIDAR, however to obtain higher resolution data over small regions the cost of flying a plane is prohibitive. This project will test the potential of a low power off-the-shelf laser as the first phase of a project to develop a LIDAR system for deployment using a drone.

### Wetland and mangrove monitoring from space

In collaboration with the Department of Parks and Wildlife, we will aim to improve the accuracy of Landsat based mapping of wetlands and mangroves. The project will require a student with competent programming ability.

### ANYTHING

If you have an idea that you think might involve remote sensing, please feel free to come and discuss it. We can design a project to suit your interests.

## 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.

### Characterising variations in the sound speed profile in the ocean off Perth

The change in sound speed with depth in the ocean has a big effect on the propagation of underwater sound, so it is important to understand its variability in order to be able to predict the resulting variability in the performance of acoustic instruments such as sonars and underwater communications systems.  Australia’s Integrated Marine Observing System (IMOS) has a number of moorings off Perth that have been collecting data since mid 2009 (see http://imos.aodn.org.au). This project would involve analysing these data sets in order to characterise the temporal and spatial variations in the sound speed profile and relating these to oceanographic phenomena such as eddies and internal waves. The influence of these variations on the propagation of underwater sound could also be investigated.

### Physics of sound production in whales (with Prof. Sasha Gavrilov)

Several species of whales produce intense, low frequency sounds of quite long duration while fully submerged. However, it isn’t clear how they achieve this feat. The aim of this project would be to come up with a physics based model of how whales produce these sounds.

## 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.

## 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.

## Dr Miles Parsons and Dr Christine Erbe

### 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 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.

## 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

Unlike other microscopy techniques, Atom Probe Tomography works by dis-assembling materials one atom at a time, and then using software to reconstruct their original 3D locations and chemical identities. It is a powerful tool for the characterisation of materials, being 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 by laboratories around the world, with almost 100 machines now installed. 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 geoscience work. 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 ionisation and evaporation processes involved in removing 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.

Read further details on the Geoscience Atom Probe facility

## 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 Mark Tucker, A/Prof Nigel Marks

### Nanodiamond synthesis using a pulsed plasma source

Nanometre sized diamonds are a scientifically and technologically important form of carbon. They are also present in large quantities in primitive meteorites, but the means by which they form is uncertain. Our computer simulations have shown that nanodiamonds can be generated from spherical shells known as carbon onions. This project investigates this process in the laboratory using a novel pulsed plasma synthesis technique. Thin coatings of nanodiamonds will be synthesised using a newly commissioned ultrahigh vacuum system coupled to a custom built power supply delivering 0.7 MW peak output. Samples will be analysed with a variety of characterisation techniques including atomic force microscopy, Raman spectroscopy and electron microscopy. Key questions to answer include how to characterise the plasma in order to optimise production of carbon onions, and the development of a filter to separate the onions from unwanted atoms and ions.

## Dr Mark Tucker, A/Prof Nigel Marks

### Ultra-thin coatings for hard disks

The read/write head on a hard disk hovers several nanometres above the recording media and protected from corrosion by an ultra-thin (less than 2 nm) amorphous carbon coating. Ever-increasing storage densities require even thinner coatings, and future technologies are likely to introduce severe thermal requirements driven by laser light passing through the coating. This project will explore the properties of ultra-thin carbon deposited using High Power Impulse Magnetron Sputtering, a new technology which contains a large flux of ionised carbon. Coatings will be analysed for their diamond-like (sp3) bonding fraction, Raman spectrum, surface chemistry, density and surface roughness. The project will also use scanning electron microscopy and atomic force microscopy to examine (and minimise) carbon particles which are detrimental to the operation of the hard disk.

## Dr Irene Suarez-Martinez, A/Prof Nigel Marks

### Structural models for activated carbons

Activated carbons are man-made nanoporous materials synthesized from virtually any carbonaceous precursor such as wood, coal or sugars. They are routinely used as absorbers in gas masks, tobacco filters and water purifiers and are often known as carbon molecular sieves. Despite their numerous applications in industry, very little is known about their structure and the few atomic-scale models available in the literature are rather poor. The broad goal of this project is the development of a computer-based nanoscale model for non-graphitizing carbons which can be used for analysis and prediction of absorbent properties of activated carbons. A variety of specific projects to achieve this objective are available, including molecular dynamics annealing simulations to understand graphitisation, quantum mechanical calculations of oxygen adsorption to assess reactivity during activation, and grand canonical monte carlo simulations of adsorption isotherms used to quantify porosity.

## A/Prof Nigel Marks

### Atomic polishing of diamond with argon clusters

Atomically flat surfaces are fundamentally important in surface science and for the fabrication of electronic devices. Large, perfectly flat terraces are easily achieved for silicon by rapid thermal annealing or ‘flashing’, but this approach fails for diamond since heating creates graphitic domains. Motivated by the new X-ray Photoelectron Spectroscopy (XPS) facility in Physics, this project will use computer simulation to explore the feasibility of smoothing the diamond surface using an argon cluster beam. The simulations will explore determine whether controlled Ar clusters can remove single atoms, carbon dimers and step edges by exploring the parameter space of cluster size, kinetic energy and incident angle. Experiments on real diamond samples would follow should the simulations suggest the process is viable, using the argon cluster beam on the XPS system in conjunction with XPS and atomic force microscopy.

## Dr Irene Suarez-Martinez, A/Prof Nigel Marks

### Junctions between Graphene and Nanotubes

Over the last 15 years a plethora of carbon nanostrutures have been developed using graphene and nanotubes as building blocks. One of the landmark concepts is a car-park-style structure in which widely-spaced graphene sheets are linked by carbon nanotubes arranged at right-angles. Recent experiments have shown that nanotubes and graphene can connect at other angles, as long as they are multiples of 30 degrees, and computer models have been developed here at Curtin to illustrate the process. The goal of this project is to explore these junctions in atomistic detail, in particular the nature of the non-hexagonal bonding at the “elbow point” of the junction. The project would primarily use molecular dynamics methods to explore the energetics of the junction, supported by quantum mechanical calculations if necessary.

## A/Prof Nigel Marks

### Radiation Damage in Graphite & Diamond

High energy particles incident onto a solid typically create a collision cascade in which a large number of atoms are displaced from their lattice sites. Understanding such processes is central to many situations, including nuclear reactors, ion accelerators and particle detectors. Recent work here at Curtin has shown that both graphite and diamond behave in a rather unusual manner. Instead of displaying a liquid-like region, as in most metals and oxide, the collision cascade contains isolated defects distributed along fractal-like trajectories. Many explanations for this behaviour have been proposed, including the low mass of carbon, the crystal structure itself, the density, and the thermal conductivity. To identify which explanation is responsible, molecular dynamics simulations will be performed on a variety of structures and systems; some of the simulations will directly mimic the laboratory, while others will be virtual experiments that have no physical counterpart, such as increasing the mass of carbon atoms.

## Interatomic Potentials for Carbon

### Dr Carla de Tomas, Dr Irene Suarez-Martinez, A/Prof Nigel Marks

The heart of a successful 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 40 different potentials have been proposed for carbon, and yet there is no single resource available to compare their performance. This project will use high-performance computers at the Pawsey Centre to perform benchmarking on large carbon systems, specifically regarding amorphization and graphitisation. The data will contribute to an established project using a combination of traditional journal articles and an online comparison tool to enable researchers from around the world to evaluate carbon potentials. Students with particular high levels of skills in computer simulation can consider a whole new data slice, such as calculation of elastic constants or simple carbon nanostructures.

## Thermal Energy Storage Materials for Technological Application

### Prof. Craig Buckley, Dr Terry Humphries, Dr Mark Paskevicius, Dr Drew Sheppard, Dr Veronica Sofianos, Dr Matthew Rowles

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.

## Development of Phase Change Materials for thermal storage applications

### Prof. Craig Buckley, Dr Terry Humphries, Dr Mark Paskevicius, Dr Drew Sheppard, Dr Veronica Sofianos, Dr Matthew Rowles

The Hydrogen Storage Research Group (HSRG) specialises in the study of materials for thermal energy storage applications. There are generally three methods to store heat: 1) Latent heat storage (phase change materials); 2) sensible heat storage (heat capacity of the material); 3) Chemical storage (breaking and forming chemical bonds). Recently, there is an increased focus on developing phase change materials as the technological and engineering requirements are reduced compared to Chemical heat storage materials. A variety of materials with melting points in the temperature region required, e.g >600 °C for Concentrating Solar Power thermal storage applications, can be employed including pure compounds or eutectic mixtures of compounds.

A project is available to develop novel materials to be used as phase change materials for thermal storage applications. This would include identification of possible phase change materials, synthesizing possible candidates and characterizing their thermal energy storage properties. This project is likely to lead to a publication in an international peer reviewed journal.

## Next Generation Battery Materials

### Dr Mark Paskevicius, Prof. Craig Buckley

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.

## 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 Alisher Kadyrov and Prof Igor Bray
Convergent close coupling approach to nuclear reactions

Understanding of nuclear reaction is of great importance for problems in cosmology and astrophysics, underpinning the distribution of matter in the universe and the evolution of stellar bodies. It also has significant ramifications for nuclear engineering, for example, in producing neutron sources for other research. Despite significant progress in studying nuclear reactions over the last two decades, both theoretically and experimentally, full understanding of the highenergy continuum of quantum states on such processes remains elusive. Using pioneering and highly successful convergent close coupling method from atomic physics, this project aims to create a new formalism that overcomes traditional problems associated with this field and which will be able to properly treat some nuclear reactions that have heretofore proved troublesome.

Objectives:

• Review the literature.
• Learn how to use supercomputers to run locally developed codes.
• Calculate cross sections for deuteron stripping reactions.

Prof Igor Bray and Prof Dmitry Fursa
Collision data for plasma 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 H2 molecules and now aim to extend it to more complex systems.

Here are theoretical and code development projects that you can participate:

Electron collisions with atoms

This project will be developed in the framework of the Jmatrix method.

Electron collisions with molecules

The present version of the CCC code will be extended to more complex molecules. A new code based on the Jmatrix method will be developed.

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.