PhD projects

Why a PhD at MQAAAstro?

The MQ Doctor of Philosophy (PhD) programme trains students to undertake research at the limits of our understanding of the Universe. During the course of their PhD, students work with leading MQ astrophysicists to further our understanding of how galaxies formed and evolved over cosmic time, how our Galaxy was assembled, how planets and stars are formed out of interstellar gas, and how stars die. At the conclusion of their studies, MQ PhD researchers are world experts in their chosen area, and have developed considerable skills in data analysis, theoretical modelling, and computer visualisation. The 3 year PhD and 4-5 year MRes+PhD programmes provide the skills required to become an independent researcher, with the ability to develop and undertake original research, and to communicate the relevance, significance and context of their work to others. The programme trains graduates for a diverse range of careers, e.g. post-doctoral research, observatory technical support, astronomy or industry data science, education (teaching, outreach), and IT.

Here are some of the other reasons to get your PhD with MQAAAstro:

• Individual research support budget.
• Opportunity for observing trips to cutting-edge research telescopes (e.g. the European Southern Observatory's Very Large Telescope in Chile).
• Links with innovative instrumentation engineers and astronomers at the Australian Astronomical Optics and CSIRO Space and Astronomy
• Living expenses and fees included in scholarship award.
• One of the fastest-growing astronomy research centres in Australia.
• High-quality research environment – ranked "well above world standard" in Astronomy and Space Science
• Diverse, international and friendly community and students and staff
• Opportunities to get involved in public outreach via our on-campus observatory, mobile planetarium, and annual  Astronomy Open Night, which attracts 2000 visitors each year
• The chance to live in vibrant Sydney while working on the beautiful Macquarie University campus.

A wide range of potential PhD topics are on offer. Students interested in particular projects or potential projects in related areas, are strongly encouraged to contact the relevant supervisor(s).

The Department of Physics and Astronomy at Macquarie University is strongly committed to diversity and equity and we welcome applications from qualified candidates of any gender, orientation, nationality and background. For more information on equity and diversity in the Department see here.

Application & eligibility information

Eligibility

Candidates must have met the formal requirements for direct entry into the PhD program at Macquarie University. The minimum requirements are:

• Completion of a Master of Research (MRes) with a grade of at least a Distinction level (75% or greater in the second year) or
• A two-year Masters degree with a major research component at Distinction level (75% or greater)*.

Don’t have a Masters degree? Information on the Macquarie MRes programme is available here. Students with an Australian Honours degree may apply for direct entry to Year 2 (the research year) of MRes programme before continuing to PhD. Bundled scholarship options are available (see below).

* Note that since grading scales may vary internationally, international candidates are encouraged to contact us at astrohdrinfo@mq.edu.au to discuss eligibility.

How to apply

Please email astrohdrinfo@mq.edu.au and attach undergraduate and Masters level transcripts, a short CV, and up to three projects you are interested in. We will connect you with the relevant supervisors, who can mentor you through the application process.

General application instructions are available here, but it is important to first go through the process above to obtain the formal support of a supervisor.

Scholarships

PhD and MRes Y2 scholarships for domestic and international students include $32,000/year for living expenses, as well as covering all program fees for the duration of the project. Certain projects have an allocated scholarship, and all others may be supported by a general domestic or international scholarship (subject to success in the competitive application process).

Further general information on scholarship opportunities can be found here. However, students should seek the advice and guidance of their proposed supervisor before commencing the scholarship application process.

Cotutelles and joint PhD programs

Macquarie University also runs cotutelle and joint PhD programs, which allows PhD students to be affiliated with Macquarie and another university overseas. More information is available here.

Studying PhD and Research Degrees at Macquarie

For general information, please visit: https://www.mq.edu.au/research/phd-and-research-degrees

Where are our Alumni now?

Our past students have been awarded fellowships, moved on to postdoctoral positions all over the world or moved to industry. Recent examples include:

• Anita Petzler (PhD 2021): Postdoctoral Fellow, CSIRO Space & Astronomy, Sydney
• Chikaedu Ogbodo (PhD 2021): Data analyist, Deferit, Sydney
• Luke Tranfa (MRes 2020): Technical Analyst, Federal IHPA
• Adriano Poci (PhD 2020): Postdoctoral Research Associate, Durham University, UK
• Michael Cowley (PhD 2019): Lecturer, Queensland University of Technology, Australia
• Erik Kool (PhD 2019): Postdoctoral Fellow, Oskar Klein Centre, Sweden
• Hiep van Nguyen (PhD 2019): Postdoctoral Fellow, Australian National University, Canberra
• Andrew Lehmann (PhD 2017): Professor of Mathematics & Physics, Institut supérieur d'électronique de Paris

Star clusters as probes of stellar evolution and nucleosynthesis

Supervisor: Dr Devika Kamath (Macquarie) and Prof. Richard de Grijs (Macquarie)

The Centre for Astronomy, Astrophysics and Astrophotonics at Macquarie University (MQAAAstro) invites Expressions of Interest from suitably qualified domestic students to complete their PhD in astronomy and astrophysics under the joint supervision of Prof. Richard de Grijs and Dr. Devika Kamath.

MQAAAstro is one of the largest and fastest-growing astronomical centres of research excellence in Australia, committed to investing in the next generation of researchers. At MQAAAstro we offer a uniquely wide range of opportunities for collaborations in observational astronomy, theoretical astrophysics, astrophotonics, instrumentation, and education. MQAAAstro has about 70 members, including faculty, postdoctoral research fellows, postgraduate students, research associates and honorary associates. Macquarie University has recently acquired the lead node of the new Australian Astronomical Optics (AAO-MQ) whose staff are engaged in astronomical instrumentation design and construction as well as astronomical research. We are also located in close proximity to CSIRO Astronomy & Space Science (CASS).

PhD Project Background:

Star clusters as probes of stellar evolution and nucleosynthesis.

Star clusters are ideal probes to test theories of stellar evolution, because they contain stars of similar age, composition, and mass. Using a  suite of multiwavelength observations of star clusters and state-of-the-art theoretical stellar and nucleosynthesis models, this project aims to address gaps in our current understanding of the physical and nucleosynthetic processes that govern the evolution of stars and the production of their elements. The observational data set includes multiwavelength spectroscopic observations from all-sky surveys such as GALAH, APOGEE, and other ground-based facilities such as those undertaken with the European Southern Observatory’s Very Large Telescope; astrometric data from the Gaia satellite; and photometric measurements .

This project will involve collaborations with leading Australian  and international research teams. The successful candidate will have ample opportunities to establish a strong network of international collaborators .

Entry requirements PhD Project Background:

The ideal candidate must have met the formal requirements for direct entry into the PhD program at Macquarie University. The minimum requirements are:

• Completion of a Master of Research (MRes) with a grade of at least a Distinction level (75% or greater in the second year) or
• A two-year Masters degree with a major research component at Distinction level (75% or greater).

Peer-reviewed research output may be taken into consideration for admission to the program.

Note that this opportunity is only open to Australian passport holders.

Expressions of Interest should be sent to Dr. Devika Kamath. Expressions of interest should include a detailed CV, transcripts of undergraduate and any Masters’ studies along with a one-page research interest statement.

For any further specific queries, please contact Prof. Richard de Grijs and/or Dr. Devika Kamath.

The Department of Physics and Astronomy at Macquarie University are strongly committed to diversity and equity and welcomes applications from qualified candidates of any gender, orientation, nationality and background. See this link for details:

https://www.mq.edu.au/about/about-the-university/faculties-and-departments/faculty-of-science-and-engineering/departments-and-centres/department-of-physics-and-astronomy/equity-and-diversity .

Stellar Variability: Redefining the Milky Way's Fundamentals

Supervisor:  Prof. Richard de Grijs (Macquarie)

We will exploit the most extensive and statistically complete catalogue of 572,338 periodic variable stars in the Milky Way to robustly quantify our galaxy's 3D mass/stellar distribution. We will conclusively determine the time evolution of the Milky Way's spiral arms and of its warped stellar disk out to distances 2–3 times as far from the galaxy's centre as our Sun. Knowing the Milky Way's structure beyond any reasonable doubt will be a breakthrough, since it is our benchmark system by which we measure external galaxies. The research project will also set the high (statistical) bar for stellar structure studies and analyses of gravitational-wave source properties, where our team has the competitive advantage internationally.

OH what a lovely molecule: using hydroxyl (OH) to seek the Milky Way's Hidden gas

Supervisors: Dr Jo Dawson and Prof. Mark Wardle

The Milky Way is permeated with interstellar gas and dust collectively known as the interstellar medium (ISM): wispy, warm and diffuse clouds of atomic hydrogen, cool, clumpy filaments of star-forming molecular gas, hot bubbles of expanding ionised gas stripped of its electrons by the radiation from high-mass stars. How, when and where does material move between these phases? How does the physics of the ISM determine when and where stars are formed? Where is the molecular mass of our Milky Way and what is it doing? In these projects you will work with radio astronomical observations of hydroxyl (OH) molecules from some of the world's best radio telescopes to help answer these questions!

1. Mapping "dark" molecular gas with SPLASH

Molecular hydrogen exists in vast clouds throughout the Milky Way, but the H2 molecules themselves produce no observable emission. When astronomers want to measure the mass and distribution of molecular gas, they typically turn to microwave emission from trace quantities of interstellar CO. Observations of CO have produced spectacular maps of our Milky Way's spiral structure, its stellar nurseries, the high-velocity gas being whipped around the Galactic bar... and have driven decades of insight into the physics of molecular clouds. However, something is missing: CO is plentiful when gas is well-shielded from dissociating radiation, but when in more diffuse environments it splits back into its constituent atoms, leaving vast clouds of "invisible" H2.

In this project you will work with fully-reduced data from SPLASH -- the Southern Parkes Large-Area Survey in Hydroxyl to attempt to reconstruct the 3D distribution of hidden molecular gas in the Milky Way using the 18-cm emission and absorption from ground-state OH molecules. You will combine radio spectral line and continuum data from SPLASH, together with archival multi-wavelength datasets, to construct a 3D map of the emitting and absorbing gas, tease apart the different ISM phases along each sightline, and measure how much of the Milky Way's molecular gas is hiding in plain sight.

2. The Australia Square Kilometre Array Pathfinder as a hydroxyl absorption machine

The Australia Square Kilometre Array Pathfinder (ASKAP) is Australia's next generation radio astronomical facility. Consisting of 36 linked dishes in the desert of Western Australia, ASKAP is pioneering new radio telescope technologies and driving some of the fastest and deepest surveys of the radio sky. In this project you will work under the guidance of Dr. Jo Dawson and astronomers at CSIRO Astronomy and Space Science, to take on leadership of the analysis of the first OH absorption data from ASKAP. This data is being taken in thr GASKAP-OH survey, which is producing the widest and most sensitive interferometric survey of OH ever undertaken! You will lead the first science, optimise data reduction strategies, and work together with the GASKAP-OH team to drive publication of the first OH science results from the ASKAP telescope. You will also help develop and test modelling code to fit and extract physical properties from the OH lines, and compare these with multiwavelength tracers to measure the mass and location of OH-rich molecular gas.

Image credit: CSIRO

The structure and evolution of disks around evolved binary stars and its implications on binary evolution.

Supervisor: Dr. Devika Kamath (Macquarie)

The threads of this study involve the intertwined stories of stellar and binary evolution. Approximately ~60% of low mass stars evolve as binaries and binarity can alter the fate of the star. We have established the presence of a stable circumbinary disks around dying binary stars: post-Asymptotic Giant Branch (post-AGB) binary stars. However, their structure and evolution, and the role played by the circumbinary disk during the evolution of the star remains elusive. This timely project is aimed at investigating these second-generation protoplanetary disks around evolved binaries. Spatially resolving these disks is a critical step in studying the poorly understood interaction processes between disks and central binary systems. Using high-angular-resolution imaging with the state-of-the-art SPHERE or the Spectro-Polarimetric High-contrast Exoplanet REsearch instrument of the 8-meter Very Large Telescope (VLT) at the European Southern Observatory (ESO), Chile, we can now spatially resolve the disks around observationally feasible post-AGB binaries. High-angular resolution imaging along with other techniques such as polarimetry, and spectroscopy will provide a gateway to determining the dust properties, disk architecture, and jet presence in these objects, allowing us to relate disk properties of post-AGB binaries to their known binary orbital parameters. The ultimate goal of this research is to understand disk evolution and quantify the impact of these disks on the binary evolution of the central objects.

The collaboration includes members in Belgium (KU Leuven), Arizona (Steward Observatory, University of Arizona), and the European Southern Observatory (ESO). Collaborative visits will form part of the study experience. The project will contain both observational and theoretical aspects.

Using Dying Stars to Reveal the Origin of Elemental Isotopes in the Universe

Supervisor: Dr Devika Kamath (Macquarie)

How are the elements in the Universe synthesised? This is one of the defining questions of astrophysics. Low- and intermediate-mass (LIM) stars (0.8 to 8Msun) are key contributors to the chemical enrichment of their host galaxies. They are major producers of elements such as carbon, nitrogen, and about half of the elements heavier than iron. However, understanding how LIM stars produce their elements remains an unsolved problem. Post-Asymptotic Giant Branch (post-AGB) stars bear signatures of the entire nucleosynthesis that took place prior to and during the chemically-rich Asymptotic Giant Branch (AGB) phase of a LIM star’s life and are therefore ideal tracers of element production. This research is aimed at revealing element production in LIM stars. Using high-resolution optical and IR spectra of post-AGB stars obtained from facilities such as the 8-meter Very Large Telescopes (VLTs) at the European Southern Observatory (ESO), the Australian-led, million-star GALactic Archaeology with HERMES (GALAH) survey, and other international surveys such as the Sloan Digital Sky Survey-IV/APOGEE, a comprehensive and homogeneous chemical analysis study will result in accurately derived elements and isotopic ratios of carbon (and possibly oxygen), amongst others. The chemical evolution of galaxies, and indeed the Universe, is governed by the chemical yields from stars. This underlines the importance of understanding how stars produce their elements by obtaining accurate stellar nucleosynthetic yields.

The collaboration includes members in Tenerife, Spain (IAC), Belgium (KU Leuven), Italy (INAF,  Osservatorio Astronomico di Roma) and other Australian institutes such as the Australian National University and Monash University. Collaborative visits will form part of the study experience. The project will contain both observational and theoretical aspects.

The Huntsman Telescope: ultra-faint galactic structures, subsecond transient searches, event cameras and daytime observing

Supervisor: Dr. Lee Spitler plus various other supervisors

The Huntsman Telescope is an astronomical imaging system that makes use of a large array of Canon telephoto camera lenses. Normally used for sports and wildlife photography, this lens array has distinct advantages over conventional telescopes for imaging faint and spatially-extended stellar structures in nearby galaxies. The PhD student on this project will have exclusive access to this new facility, which is at Siding Spring Observatory in Australia. A variety of projects are available in areas related to: subsecond transient searches, daytime observations and new technology development (e.g. event-based cameras).

Adapting the Huntsman Telescope for laser communications

Supervisor: Dr. Lee Spitler, Dr. Haoran Ren, Prof. Judith Dawes

We propose to adapt the huntsman telescope for a novel application in free-space optical communications. We will create a diffractive optical component that can be incorporated into the Huntsman Telescope for free-space optical communications, for example, communicating with line-of-sight between buildings.

We are working on the fabrication of the diffractive optical component with external collaborators. The student's project would entail the characterisation of the diffractive optical component and its integration into the Huntsman Telescope in remote New South Wales.

Stellar Collisions

Supervisor: Prof. Orsola De Marco (Macquarie)

In the last few years powerful telescopes have come on line that can monitor big swaths of sky every night. This has created the first detailed movie of the night sky and astronomers have been surprised to see just how many flashes can be seen. Some of these flashes are due to stellar pairs interacting with one another. When this happens bright explosions and outbursts take place which we can now finally observe. Yet when we try to reconstruct what goes on during these interactions we find that it is not so easy. Without a viable theory of stellar interaction many mysteries go unsolved. Among them the understanding of several types of supernovae, gamma ray bursts and the emission of detectable gravitational waves.

In this suite of projects the student will learn to use a number of fluid dynamic computer codes to model stellar interactions and collisions. The student will be able to choose one of a number of sub-projects starting from the interaction of planets with their mother star to the interaction of much more massive stars in very eccentric orbits.  Each project is in collaboration with national and international partners. For more information click here: http://web.science.mq.edu.au/~orsola/PhD.htm

Huntsman Probes the Cosmic Web - characterising the foreground galactic circus

Supervisor: Dr Lee Spitler (Macquarie), Dr Joanne Dawson (Macquarie)

Like cirrus clouds obscuring the sky from the Earth’s surface, Galactic cirrus are vast clouds of interstellar gas and dust in our own Milky Way that absorb light from background galaxies. While these clouds can present a challenge to astronomers aiming to image the distant universe, they also present an opportunity to study the local interstellar medium in unprecedented detail. This project will use the new Macquarie University Huntsman Telescope ( https://www.instagram.com/astrohuntsman/ ) to image ultra-faint Galactic cirrus. You will develop image-processing techniques needed to disentangle this foreground structure from background galaxies and ultimately study the properties of turbulence in the interstellar medium.  This is a cotutelle project co-supervised at the University Paris Saclay, and the successful student will be expected to spend at least 1 year of their PhD in Paris working with Prof Marc-Antoine Miville-Deschenes.

Fornax3D - A new survey of the Fornax Galaxy Cluster with MUSE

Supervisor: Dr Richard McDermid (Macquarie)

The collaboration includes members in Chile (ESO) and Europe (including MPIA Heidelberg, IAC Tenerife, and INAF Rome), and visits to these institutes will form part of the study experience. Both theoretical and observational aspects will be explored.

Galactic Archaeology

Supervisor: A/Prof. Dan Zucker (Macquarie) and Gayandhi De Silva (AAO Macquarie)

The field of Galactic Archaeology – the detailed study of stars in our Galaxy and its nearest neighbours in order to uncover clues to their formation and evolution – is entering a new era with the commissioning of the revolutionary new HERMES spectrograph. HERMES, being built for the Anglo-Australian Telescope, will obtain detailed elemental abundances and precision radial velocities for over a million stars in the Milky Way in the GALAH (GALactic Archaeology with HERMES) survey. GALAH and other projects now underway or starting soon (e.g., the ESA space mission Gaia) will open new frontiers in our understanding of the formation and evolution of the Galaxy. In this research area, you will have the opportunity to work with Dr. Daniel Zucker and the HERMES Super Science Fellows at Macquarie University, as well as with other members of the GALAH team and collaborators at universities and institutes in Australia and around the world.

An ultra-stable infrared spectrograph to search for earth-like planets

Supervisor: Dr Christian Schwab (Macquarie)

The discovery of Earth's twin, a habitable world in another stellar system, is one of the most remarkable scientific endeavours of our time. This project will set up a testbed instrument, which combines novel technologies from astrophotonics and adaptive optics into an innovative spectrograph design that will improve measurement precision in the near-infrared spectral range, working toward the detection of rocky planets around small and red stars.

The PhD candidate in this project will work with Dr. Christian Schwab to develop the optical and mechanical design for an ultra-stable, single-mode spectrograph and integrate a prototype in the Macquarie University lab. The student will also test the spectrograph on-sky at the Macquarie University campus observatory and use it to demonstrate high-resolution infrared spectroscopy at a large adaptive optics facility.

The student will learn to work with a leading optical raytracing software (Zemax) to model optical systems as well as CAD software to design the optical mechanics for the spectrograph. In the lab the student will work to acquire expertise in assembling and aligning optical and laser systems, learn to integrate vacuum equipment and and gain experience operating instruments at small and large telescopes. If time permits, we will couple our spectrograph with the SCExAO adaptive optics system at the Subaru telescope facility on Mauna Kea, Hawai'i.

The  RHEA spectrograph, built at Macquarie, is currently being tested at the Subaru Telescope.  This instrument works in the visible part of the spectrum; the PhD candidate will work at a sightly larger infrared single mode spectrograph.

Satellites and Stellar Streams in the Local Group

Supervisor: A/Prof. Dan Zucker (Macquarie)

Galaxies like our Milky Way form by accreting smaller systems, and this process of galaxy cannibalism continues to the present day: the dwarf satellites orbiting the Galaxy and M31, its nearest large neighbour, are survivors, while the victims are stretched across the sky in stellar streams. These satellites and streams, many of them revealed by wide-area astronomical surveys like SDSS (the Sloan Digital Sky Survey) and PAndAS (the Pan-Andromeda Archaeological Survey), probe the conditions of galaxy formation in the early Universe and the behaviour of Dark Matter on the smallest scales. In this research area you will have the opportunity to work with Dr. Daniel Zucker at Macquarie University, as well as with collaborators at other universities in Australia and overseas.

The impact of environment on galaxies as probed by the SAMI and Hector Galaxy Surveys

Supervisor: Dr Matt Owers (Macquarie)

Galaxy properties, such as morphology and rate of star-formation, correlate strongly with the environment in which a galaxy resides. The sense of this correlation is such that galaxies that live in very dense clusters of galaxies generally have elliptical morphologies without ongoing star-formation, whereas galaxies that live in lower density environments are more likely to be spirals with ongoing star-formation, much like our own Milky Way galaxy. An added complexity to this picture is that the densest regions in the Universe---rich galaxy clusters---are not static but are themselves evolving dynamically by hierarchical structure growth. That is, clusters accrete galaxies from low-density regions that are dominated by star-forming spiral galaxies, while the dense centres of clusters are dominated by E and S0 galaxies; this strongly indicates that galaxies accreted onto clusters must undergo significant, environment-driven transformation. Understanding how this environment-driven transformation takes place is one of the fundamental challenges in modern astrophysics.

This field is currently undergoing a rapid transformation thanks to ongoing surveys such as the SAMI Galaxy Survey (http://sami-survey.org), and its successor, the Hector Survey (https://www.aao.gov.au/technology/new-instruments/hector). These surveys are providing spatially resolved spectroscopy for  thousands of galaxies across a range of environments, allowing new and improved ways to attack the problem of environment-driven galaxy transformation. Various avenues for PhD projects supervised by Dr. Matt Owers are available within this field, using data collected during the SAMI Galaxy Survey, and preparing for the upcoming Hector Survey. Projects all involve the potential for collaboration with both Australian and international astronomers.

Novel spacecraft optical systems

Supervisor: Prof. Jon Lawrence, Dr. Lee Spitler

The AAO are innovating in the area of novel space-based optical systems for applications outside of astronomy. For example, we are working on an agile steering mirror than can point a telescope to another location on the Earth within a fraction of a second. Technology such as this can increase the mission efficiency for projects like the Aquawatch mission, which will monitor water quality across the entire Australian continent. Various HDR projects are available: simulating impact of new capabilities, designing custom optical systems and space qualifying our technology. Reach out to the supervisors for more information.

Measuring galaxy star formation rates

Supervisor: Andrew Hopkins (AAO Macquarie)

The process of star formation in the universe is intimately linked to the evolution of galaxies. To understand galaxy properties, researchers typically make assumptions about the distribution of masses in a newly formed population of stars, with the same assumption applying at all times and in all galaxies in the universe. This “universal” initial mass function (IMF) is poorly constrained observationally, and there are many results from the past two decades suggesting that the IMF is not universal, that is, it may differ between galaxies and at different epochs in cosmic history. This project will look at refining the way that observations can be used to constrain measurements of the stellar IMF through development of so-called population synthesis tools, models linking stellar evolution with observational properties of galaxies, in order to identify new observational metrics that may be able to probe the shape and evolution of the IMF in different galaxy populations.

Understanding Star Formation

Supervisor: Andrew Hopkins (AAO Macquarie)

The rate at which new stars form in galaxies like our own Milky Way is a fundamental attribute, and one that is intimately tied to their formation and evolution. Galaxy star formation rates have been measured for many decades, and we have a good understanding of the broad picture of the star formation history of the universe. None of the metrics used to estimate star formation rates in galaxies is particularly accurate, however, and can be uncertain by as much as an order of magnitude or more. This project will bring together data spanning the electromagnetic spectrum to improve star formation rate estimates, linking new data from the latest generation of radio surveys such as EMU (Evolutionary Map of the Universe) with spectroscopic measurements from wide and deep surveys including the GAMA (Galaxy And Mass Assembly) survey to develop a robust quantitatively constrained estimate of galaxy star formation rates. This will enable us to improve and robustly constrain the star formation history of the universe, and to understand how it is partitioned between galaxies of different masses and types.

From dust formation to star formation in galaxies

Supervisors: Tayyaba Zafar (AAO Macquarie), Matt Owers (Macquarie)

Dust absorbs light, particularly at UV and optical wavelengths. The dust analysis and correction are very important to estimate dust-corrected metallicity, star-formation rates, and other physical properties of galaxies. Balmer decrement (Flux ratio of H-alpha to H-beta emission lines) is used as a proxy for dust and is usually used to estimate galaxy dust properties. However, it is important to determine total dust properties in a galaxy to understand its origin and ongoing star formation. Dust attenuation curves are crucial to derive the physical properties of galaxies and yet very few measurements are available at higher redshifts. The longest possible wavelength coverage of the spectral-energy distributions (SEDs) of galaxies allows deriving the best attenuation curves. Furthermore, a comparison of dust attenuation with Balmer-decrement is important to understand optical and total dust properties. To determine dust properties of galaxies of different morphological types and at different distances, we have integral-field data available from SAMI and MAGPI surveys and more data will be coming from the ongoing HECTOR survey. The spatially resolved data combined with multi-band photometry will enable us to understand fundamental key questions about dust properties at larger distances.

Using Open clusters to probe the Galaxy

Supervisor: Gayandhi De Silva (AAO Macquarie)

Open clusters are the ideal tools for probing our Galaxy's chemical and dynamical evolution. They are mono-age and mono-abundance population that can be used to trace the star formation history of the Galaxy. However to-date only a handful of open clusters, limited to the solar neighborhood have been studied via high resolution spectroscopy.

This project will source original data from the new high-resolution high multiplex HERMES instrument on the Anglo-Australian telescope to determine the chemical content, motions and ages of previously unstudied open clusters probing further out into the Galactic disk. The results will give insights into Galactic trends and help to piece the puzzle of how our Galaxy formed and evolved. The research will involve collaborations with other experts locally and internationally. This project offers the opportunity to visit the 4m Anglo-Australian Telescope in Coonabarabran, NSW.

Spectroscopy and the Composition of Stars in Globular Clusters

Supervisors: Gayandhi De Silva (AAO Macquarie) and Simon Campbell (Monash)

Globular clusters are the oldest and most populous stellar aggregates in existence. Recent studies have shown that the stars in globular clusters show abundance patterns that are unique to the clusters. We do not know why they are not seen in the Galaxy, but only within the globular clusters. They may even be the remnants of collisions between dwarf Galaxies and our Milky Way. A fuller understanding requires us to determine the abundances of many stars in many clusters and to compare with theoretical models so we can see what stars produced the existing patterns. We will source original data form the world's largest telescopes and then analyse this to determine the abundances of key species in globular cluster stars: perhaps Li, C, N, O, Mg, Al, Fe as well as the heavy elements made by neutron capture, such as Sr, Y, Zr, Ba, La. Stellar models that can produce these species will be compared with the abundances we measure. This project offers the opportunity to visit the 4m Anglo-Australian Telescope in Coonabarabran, NSW and/or the 8m Very Large Telescope at Paranal Observatory in Chile.

Unveiling the connections between gas, stars and star-formation in nearby dwarf galaxies

Supervisor: Ángel López-Sánchez (AAO Macquarie)

Large galaxy surveys such as CALIFA (Sanchez et al. 2012, 2014, 2016), MaNGA (Bundy et al. 2015) and the SAMI Galaxy Survey (Croom et al. 2012, Bryant et al. 2015) use Integral Field Spectroscopy (IFS) to provide a detailed view of how galaxies formed and evolved. These surveys mainly target the “normal” galaxy population, but dwarf galaxies tend to be under-represented. In addition, many of the systems observed are too far away to be well resolved and the (scarce) neutral hydrogen data available come from single-dish radio observations, lacking any spatial information. Interferometric observations of the 21-cm HI emission (that trace the distribution and kinematics of the neutral gas within and around the galaxies) are essential in order to obtain a coherent and comprehensive picture (e.g. Lopez-Sanchez et al. 2012a, 2015, Gavilan et al. 2013, Ascasibar et al. 2015), providing powerful constrains on the physical processes that regulate the star formation rate and the build-up of stellar mass over cosmic time.

We are currently obtaining high-quality 2D optical galaxy spectra of nearby dwarf galaxies with available 21-cm HI interferometric radio data using the KOALA Integral Field Unit in conjunction with the AAOmega spectrograph at the 3.9m Anglo-Australian Telescope. Our sample of "HI - KOALA IFS Dwarf galaxy Survey" (Hi-KIDS), represent the subset of low-luminosity, metal-poor galaxies undergoing strong and short-lived episode of star formation, in many cases triggered by interactions (e.g .Bravo-Alfaro et al. 2004, Lopez-Sanchez 2010, Lopez-Sanchez et al. 2012a) and are perfect targets to trace gas accretion, massive stellar feedback and their influence on other properties (e.g., chemical composition, kinematics).

We are seeking a highly motivated PhD student to work on the analysis of the high-quality data obtained for Hi-KIDS. The student will gain expertise in the reduction and analysis of Integral Field Spectroscopy (IFS) data, as well as data science tools needed for Astronomy, and analyse the KOALA and radio data to improve our understanding of the link between the neutral hydrogen gas and the fuelling of star formation in dwarf galaxies..

In particular, the PhD student will

• help in the Hi-KIDS observations at the 3.9m AAT using KOALA+AAOmega.,
• help to develop Python scripts for analysing and visualizing IFS data and the combination of the radio + optical data.
• perform a global analysis of the physical (mass, star-formation rate, extinction, electron temperature and density, excitation), chemical (ionic and total abundances of helium, oxygen, nitrogen, sulphur, neon, argon...) and kinematical (rotation of the galaxy, distortions due to interactions, existence of outflows or inflows of gas) properties of the Hi-KIDS galaxies.
• study the scaling relationships of star-forming galaxies adding the HI-data: mass-metallicity relation, star-formation efficiency, Schmidt-Kennicutt relation, and their comparison with the results provided by samples of larger galaxies,
• compare the observations results with the predictions given by theoretical models and galaxy evolution simulations.

This extensive and comprehensive multi-wavelength research of dwarf galaxy properties will be released publicly as legacy. Hi-KIDS will provide a unique benchmark of high-quality IFS optical data, new tools for analysing IFS data, key scientific observational and theoretical results about the nature and evolution of dwarf galaxies, and it will be pioneer for the multi-wavelength galaxy surveys that are expected in the next decade.

Revealing dust properties in distant environments

Supervisor: Tayyaba Zafar (AAO Macquarie)

Cosmic dust plays a crucial role in the formation of stellar populations. The extinction curve is a standard tool to study dust absorption and scattering at optical/ultra-violet wavelengths. Extinction curves reveal information about dust grain sizes, their compositions and properties. Typically at higher redshifts, the extinction curves from the Local Group (i.e., Milky Way, Large and Small Magellanic Clouds) are used as a reference to derive extinction in those environments. Quasars and gamma-ray bursts are the brightest sources in the universe and can be seen up to the epoch of reionisation. There are plenty of data available (both spectroscopic and photometric) from various telescopes for these high-redshift objects from the ultra-violet to the near-infrared to generate their spectral energy distributions and hence derive individual extinction curves rather than using reference Local Group extinction laws. The analysis so far used smaller samples of quasars and gamma-ray bursts indicate featureless and steeper extinction curves at higher redshifts (Zafar et al. 2015, 2018). This suggests different dust grain populations and/or effects of radiation fields in the vicinity. This project with a larger sample will help in understanding the transition of extinction curves at higher redshifts and inferring various dust populations.

This project includes the collaboration of University of Copenhagen (Denmark) and Leicester University (UK). The project has observational aspects and the student will be involved with observing and using European Southern Observatory, Very Large Telescope data.

Searching for faint absorbing galaxies in emission

Supervisor: Tayyaba Zafar (AAO Macquarie)

Quasars are very luminous and distant sources. Their spectra reveal absorption lines of the intergalactic medium between the quasars and us. Broad and strong absorption lines are seen when quasar line of sight passes through a dense gaseous cloud or galaxy. Although there is enough information available for these dense absorbers about their gas, metals, and dust from absorption studies, very little is known about their hosting galaxies. It is important to target these line of sight absorbers in emission to measure the galaxy properties, such as which galaxies they come from, are they galaxies similar to other galaxies at the same distance, and how their luminosity and number density behave at greater distances. As these absorbers come from random sightlines (where their exact location on the sky is not known) and being faint and farther away, they are hard to find. Searches over the past two decades have only detected ~0.3% of absorbing galaxies in emission.

With high spatial resolution instruments we are now able to detect these faint galaxies. The aim will be to use the existing European Southern Observatory, Very Large Telescope instruments to hunt well-defined cases. Involvement with up-coming instruments like MAVIS is also a key opportunity to get involved with instrument science and subsequently use this new instrument to further the goals described above. The project includes collaboration with the University of Copenhagen (Denmark) and Laboratoire d’Astrophysique de Marseille (France) and collaborative visits will be conducted to acquire more experience.

Digging hidden quasars with TAIPAN

Supervisors: Tayyaba Zafar and Jon Lawrence

The TAIPAN instrument at the UK Schmidt telescope is currently under commissioning. The instrument is a fibre-fed instrument where up to 100 robotic fibres (starbugs) cover the field-of-view of 6 degrees. The instrument has the facility of remote observing. We are currently running a quasar project during the commissioning of the instrument. We are targeting the Gaia fields after applying a selection of the e Wide-field Infrared Survey Explorer (WISE) to search for the (dusty) quasars. Previously from a dataset smaller than TAIPAN data already showed around 90% of targets with such selection criteria turned out to be quasars (Krogager et al. 2016).

The project will involve observing and data analysis with Taipan for the project, data handling and processing, filtering the stars and quasars and combining the TAIPAN quasar data with Gaia and WISE photometry to generate spectral energy distributions and fitting for dust and its properties. As instrument is in commissioning phase, the data quality will also be determined. The TAIPAN instrument is a proto-type of the Giant Magellan Telescope MANIFEST instrument, the work will further be applied advancing the MANIFEST concept.

Astrophotonics

Supervisor: Simon Ellis

Astrophotonics is the application of photonics to astronomical instrumentation.  AAO-MQ is at the forefront of this young and rapidly developing field.  Photonic technologies have the potential to transform astronomical instruments, through miniaturisation, stability, and new functionalities impossible with classical optics.  There are multiple directions of study available for the interested student including both theoretical modelling and laboratory based work, e.g.:

• Miniature spectrographs.  The size of astronomical instruments scales with the diameter of the telescope, and instruments for the next generation of Extremely Large Telescopes will be enormous and enormously expensive.  Astrophotonics can break this dependency with multiple replicated modular spectrographs a few cm in size.  This project will consist of modelling, designing and testing miniature spectrographs.
• OH suppression.  AAO-MQ is a world leader in a radical new technology which uses speciality optical fibres to filter atmospheric emission lines from astronomical spectra, thereby enabling deep observations of the distant Universe.  This project will develop this technology for future instruments, in particular investigating and testing the techniques necessary to allow large-scale instruments for Extremely Large Telescopes.
• Silicon photonics.  Silicon photonics has extremely high potential due to the ability to manufacture chips at commercial foundries using CMOS manufacturing techniques.  Chips of only 1cm x 1cm can contain thousands of devices – delivering truly miniature instruments.  However application to astronomical instruments is currently difficult due to the losses injecting light into the chips.  This project will investigate methods to overcome these difficulties and apply silicon photonics to OH suppression and wavelength calibrations.

Multi-object adaptive optics

Supervisor: Simon Ellis

The full potential of the next generation of Extremely Large Telescopes comes from the combination of their light collecting power and the exquisite angular resolution at the diffraction limit of the telescope.  Exploiting the diffraction limit of the telescope requires using adaptive optics to correct for the effects of turbulence in the Earth’s atmosphere.  This project will study a new concept for deployable wavefront sensors and deployable adaptive optics units to allow multi-object adaptive optics, i.e. the ability to correct the effects of turbulence locally at any location over a large field of view.