Astronomy PhD projects

Astronomy PhD projects

PhD Projects on Offer in the Department of Physics and Astronomy at Macquarie University focused on Astronomy and Astrophysics

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The projects below are available for possible PhD projects. We encourage you to read them, follow the hyperlinks to read background information on the science related to the projects, and email the Chief Project scientist (bold font), for more information. If you are interested to apply to do a PhD on a particular project please submit your Expression of Interest application by the next deadline by clicking HERE.

Mapping the structure and environment of the gaseous Milky Way

SPLASH_imageDr. Joanne Dawson
joanne.dawson@mq.edu.du - Macquarie University/CASS

Mark Wardle
mark.wardle@mq.edu.au - Macquarie University
 

Naomi McClure-Griffiths
Naomi.McClure-Griffiths@anu.edu.au - CASS

Interstellar hydroxyl (OH) is a versatile probe of star-forming and pre-star-forming gas in the Milky Way, and a promising tracer of what is known as the “dark” interstellar medium (so called because it is invisible to standard spectral line tracers). This hidden material may make up as much as half of the neutral gas mass in some parts of the Milky Way, and is a vital missing link in the evolutionary cycle of the Galaxy’s gas. The Southern Parkes Large-Area Survey in Hydroxyl (SPLASH) is the first splash2large, sensitive survey of OH in the Milky Way, and is pioneering the field of OH astronomy. The student will work with newly-processed SPLASH data in order to investigate the distribution and physical properties of OH-rich gas and link these to major outstanding questions about ISM evolution and the structure and environment of our Milky Way Galaxy. Models of OH excitation will be used directly in the interpretation of the observational data, with potential directions including developing OH as a barometer of the physical conditions in the local environment, and as a tracer of complex, entangled structures along the line of sight. Potential follow up work includes observing projects with ASKAP, Australia’s pathfinder for the SKA.

Mapping the Galactic Magnetic Field with Masers

dawson_mapping_the_gal_fieldDr Joanne Dawson
joanne.dawson@mq.edu.au - Macquarie University 

Dr Jimi Green
james.green@csiro.au - CSIRO Astronomy and Space Science

MAGMO Collaboration

It is believed the Milky Way has magnetic fields threaded throughout its spiral structure with unusual and unexplained reversals in direction. What does this mean for our Galaxy and how will it influence its evolution? This project will explore these fundamental questions, by utilising new radio observations of astrophysical masers (‘microwave lasers’) to map our magnetised Milky Way. For the first time, through cutting-edge data from Australian telescopes, we will be able to trace the magnetic fields around newly-forming stars along the spiral arms of our Galaxy.

The challenge in studying the spiral and magnetic structure of our Galaxy is finding a tracer which can be observed throughout the Galaxy, can be accurately positioned in space, and can provide the vital information on the magnetic field itself. Astrophysical masers from interstellar molecules are perfect for this. The 6.7-GHz methanol maser is an ideal tracer of the main structural features of our Galaxy, since its intrinsic and exclusive relationship with high-mass star formation closely locks it to the spiral arms. On the other hand, 1.6-GHz hydroxyl masers, which have a strong magnetic dependence, clearly demonstrate the strength and direction of in-situ magnetic fields via Zeeman splitting of the maser transition. This project will combine state-of-the art observations of methanol and hydroxyl masers from the Parkes Telescope Methanol Multibeam survey [1] and its companion, the Australia Telescope Compact Array MAGMO survey [2]. By combining hundreds of maser detections from these two powerful datasets, the student will derive a new picture of the structure and magnetic field of the Milky Way.

This project is in collaboration with CSIRO Astronomy and Space Science (CASS), Australia’s premier radio astronomy facility and key partner in the world’s largest radio telescope, the Square Kilometre Array (SKA). The student will work in tandem with supervisors at Macquarie and CASS, reducing and analysing radio astronomical data from world-class telescopes, and developing their research in a vibrant and active astronomy community. The student will gain a high level of expertise in key aspects of telescope operations and data processing, and will benefit from the strong international standing of the CASS student programme, placing them in an excellent position to embark on their future careers.

[1] Green et al. 2009, MNRAS, 392, 783
[2] Green et al. 2012, MNRAS, 425, 2530

The Huntsman Telephoto Array: ultra-faint imaging of galaxies

huntsmanDr. Lee Spitler
lee.spitler@mq.edu.au - Macquarie University/AAO

Dr. Anthony Horton
anthony.horton@aao.gov.au - AAO

The Huntsman Telephoto Array is a new 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 [1]. The PhD student on this project will have exclusive access to this new facility, which will be based at Siding Spring Observatory in Australia.

By identifying new dwarf galaxies and stellar streams around nearby galaxies their historical record of formation can be recovered and we can determine how galaxies assembled their mass [2,3]. This project will provide an exciting combination of hands-on astronomy instrumentation, image processing and astrophysical analysis. The data obtained with be combined with observational data at other wavelengths, including radio maps of neutral hydrogen gas from the WALLABY on Australia’s ASKAP telescope [4]. The Huntsman system is a precursor for a Macquarie-led space-based cubesat facility, the Australian Space Eye [5,6]. 

[1] Abraham, van Dokkum, 2014, Pub. of the Astro. Soc. Of the Pacific, 126, 55
[2] van Dokkum, Abraham, Merritt, Astrophysical Journal Letters, 2014, 782, L24
[3] van Dokkum, et al., 2015, Astrophysical Journal Letters, 798, L45
[4] http://www.atnf.csiro.au/research/WALLABY/
[5] Horton, et al., The Australian Space Eye: low surface brightness imaging from space, Proceedings of the 15th Australian Space Research Conference (2016), accepted
[6] Reisenfeld, Spitler, Horton, 2015, The Australian Space Eye: Ultra-Faint Astronomy Imaging from Space, 33rd AIAA International Communications Satellite Systems Conference and Exhibition

For more details about the project click here: https://www.facebook.com/HuntsmanEye .

For more details about the host group and research centre click here: http://web.science.mq.edu.au/directory/listing/person.htm?id=lspitler

http://astronomy.mq.edu.au

The Rise of the Jellyfish: Galaxies caught in the act of environmentally driven transformation

jellyfidhDr. Matt Owers
matt.owers@mq.edu.au - Macquarie University/AAO

Prof.Warrick Couch
warrick.couch@aao.gov.au - AAO

Macquarie University & Australian Astronomical Observatiory

Galaxies in high density (groups and clusters) and low density (field) environments display different properties; this observational fact has been known for over 80 years. The difference is in the sense that galaxies that live in dense environments are more likely to have spheroidal morphologies with little ongoing star formation while galaxies in low density environments generally have disk-like morphologies and are still forming stars. These differences must be reconciled with the hierarchical formation of groups and clusters. In this hierarchical scenario, clusters and groups of galaxies grow in both mass and galaxy number density by accreting matter from their lower density surrounds. In order to be consistent with the observation of little or suppressed star formation in dense environments, the star formation of the infalling galaxies must be halted. Over the past few decades, much effort has been devoted to understanding the underlying physics driving this suppression, or quenching, of star formation. No single dominant mechanism has been identified to date and there are conflicting results found for the significance and timescales of environmental processes.

In this project, the PhD candidate will study the enigmatic “jellyfish galaxies” and their surrounding environment. Jellyfish galaxies are found in massive clusters of galaxies and exhibit one-sided trails of extremely blue knots and filaments [1].These knots and filaments are interpreted as the manifestation of hot, young stars formed in-situ within gas that has been stripped from the parent galaxy, indicating the jellyfish are in the process of being transformed by the environment. Observing galaxies “caught in the act” of being strongly transformed by the environment will lead to a better understanding of the dominant physical mechanisms at play.

The PhD candidate will use integral field spectroscopy (from the new KOALA instrument on the 3.9m Anglo-Australian Telescope and the WiFeS instrument on the 2.3m telescope at Siding Spring Observatory) to investigate the impact of this gas stripping on the star forming properties of the galaxy, and also to investigate the properties of the blue knots and filaments in the tails. Furthermore, the PhD candidate will use the combination of X-ray information (provided by the Chandra and XMM-newton satellites), which traces the hot intra-cluster medium, and multi-object spectroscopy (from the AAOmega instrument on the AAT), which traces the dynamics of the cluster through galaxy velocities, to obtain a detailed understanding of the environmental conditions required for the formation of a jellyfish galaxy.

[1] Owers, M.S., Couch, W.J., Nulsen, P.E., Randall, S.W., The Astrophysical Journal Letters. 750, L23 (2012).

Stellar Collisions              

stellar collisionsProf. Orsola De Marco
orsola.demarco@mq.edu.au - Macquarie University

Prof. Mark Wardle - Macquarie University
A/Prof. Daniel Price - Monash University
Dr. Jan Staff - Florida State University
Dr. Jean-Claude Passy - Argelaender Institut, University of Bonn

Many stars are born in pairs close enough to each other that they interact during their lives. Stars also can interact with planets that orbit them. When they do, they produce all manners of explosions, jets, nebulae and even produce detectable gravitational waves. Today, new surveys are detecting these interactions in greater and greater numbers, and there is an increasing need of models that can explain these phenomena. Using 3-dimensional hydrodynamics models our group aims to understand the physics of these interactions in order to provide a more complete description of how stars live and dye in the presence of a companion [1,2,3]. We also use 1D and analytical tools as well as observations from space and ground-based telescopes [4,5].

Within the context of binary interactions a range of project are available both in observations and theory. The prospective student will be able to chose a project depending on their inclinations.

For more details about the project click here: http://web.science.mq.edu.au/~orsola/CommonEnvelopes.html

For more details about the host group and research centre click here: http://web.science.mq.edu.au/~orsola/Research.html

http://www.mq.edu.au/research/research-centres-groups-and-facilities/secure-planet/centres/centre-for-astronomy,-astrophysics-and-astrophotonics-mqaaastro

[1] Passy et al. 2012, ApJ 744, 52
[2] Staff et al. 2016a, MNRAS 458, 832
[3] Staff et al. 2016b, MNRAS 455, 3511
[4] Tocknell et al. 2014, MNRAS 439, 2014
[5] De Marco et al. 2015, MNRAS 448, 3587

Galactic Archaeology

gal_archA/Prof. Dan Zucker
daniel.zucker@mq.edu.au - Macquarie University/AAO

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.

Satellites and Stellar Streams in the Local Group

sat and stellar streamsA/Prof. Dan Zucker
daniel.zucker@mq.edu.au - Macquarie University/AAO

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.

MUSE The FORCE: MUSE Used to Spectroscopically Explore The FORnax Cluster Environment 

muse
richard.mcdermid@mq.edu.au - Macquarie University


MUSE is a revolutionary new instrument on the European Southern Observatory (ESO) Very Large Telescope (VLT), which allows us to make detailed maps of the motions and chemistry of gas and stars in galaxies. This project will be part of a new international survey of the nearby Fornax galaxy cluster using MUSE, together with a  wealth of ancillary data, to study tens of galaxies in unprecedented
detail. Multiple avenues of PhD study are possible for the student, including:

- Studying stellar ages and chemistry: when and where did stars form?
- Stellar dynamics - what are the orbits of the stars, and what can they tell us about dark matter, supermassive black holes, and galaxy assembly?
- The interactions between galaxies and the cluster environment - how are galaxies altered by their proximity to other galaxies?

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.

Joint PhD Projects with National Observatories

What shapes galaxies?

Caroline Foster
caroline.foster@aao.gov.au - AAO

Lee Spitler
lee.spitler@mq.edu.au - Macquarie University/AAO

Measuring the intrinsic (or three-dimensional) shape of galaxies is a non-trivial task as it is complicated by projection effects. The intrinsic shape of galaxies is a fundamental property that is directly influenced by various galaxy formation processes. One can obtain meaningful constraints on the intrinsic shape of galaxies by combining photometric and kinematic maps for statistical samples of galaxies.

The advent of multi integral field unit spectrographs are enabling the observation of statistically meaningful samples of kinematic maps for the first time. Using data from the SAMI Galaxy Survey, this project will explore and identify the physical mechanisms that influence the intrinsic shape of galaxies. This will provide new constraints for galaxy formation models.

This project involves collaboration within the SAMI Galaxy Survey, the use of data from the Anglo Australian Telescope (Australia's largest optical telescope) and the possibility to be involved in observing and data acquisition. The selected student will acquire experience in developing code, expertise with modern statistical techniques and integral field spectrograph data analysis skills that are easily portable to other fields.

Three Projects on the Milky Way, Star Formation and the Interstellar Medium

3 projectsDr. Joanne Dawson
joanne.dawson@mq.edu.du - Macquarie University/CASS

How do galaxies convert their reservoirs of gas into stars? How do supernova explosions and stellar winds affect the evolution of the interstellar medium? How do cold, dense star-forming clouds condense from warmer gas? What is the structure of our Milky Way Galaxy?

MQAAAstro is offering a number of projects in collaboration with staff at CSIRO Astronomy and Space Science (CASS), Australia’s premier radio astronomy facility and key partner in the world’s largest radio telescope, the Square Kilometre Array (SKA). Students will work in tandem with supervisors at Macquarie and CASS, reducing and analysing radio astronomical data from world-class telescopes, planning and carrying out their own observing programmes, interpreting their findings in the context of theoretical models, and developing their own research directions in a vibrant and active astronomy community. These projects not only offer the opportunity to make genuine scientific advances in the fields of the interstellar medium, galaxy evolution and star formation, but also to get involved “from the ground up” in SKA pilot science, via the Australia Square Kilometre Array Pathfinder telescope (ASKAP) which is now open for science operations. Students will gain a high level of expertise in key aspects of telescope operations and data processing, and will benefit from the strong international standing of the CASS student programme, placing them in an excellent position to embark on their future careers.

Calibrating the HISA Galaxy

hisaDr. Joanne Dawson
joanne.dawson@mq.edu.du - Macquarie University/CASS

Naomi McClure-Griffiths
Naomi.McClure-Griffiths@anu.edu.au - CASS

Understanding the lifecycle of the interstellar medium (ISM) as it evolves from warm atomic gas to cold molecular gas and eventually to stars, is a vital part of understanding how galaxies themselves form, live and die. This understanding requires accurate measurements of the interstellar gas. The absorption of bright radio continuum by neutral hydrogen atoms is one of the most direct and accurate probes of the temperature and abundance of the atomic ISM. However, observations are limited to sight-lines that contain bright continuum sources such as distant active galaxies. Conversely, the self absorption of hydrogen spectral line emission by foreground gas (HI Self-Absorption: HISA) can provide spectacular maps of the distribution and structure of the cool interstellar medium, but with limited ability to make quantitative measurements of its properties.

The student will bridge the gap between these two complementary regimes, by using world-class radio telescopes to observe and analyse large samples of continuum background sources towards HISA clouds. Not only will this provide a vital scale with which to calibrate HISA measurements throughout the entire Milky Way, but it is also a stepping stone to future SKA science, for which HI absorption measurements are a key science driver. The project also has large scope for overlap with the SPLASH project (described above), with possible directions including assembling sets of multiple tracers (such as OH and CO) to follow the gas through multiple stages of its evolution. Potential follow up work includes observing projects with ASKAP, Australia’s pathfinder for the SKA.

High-altitude star-formation and the superbubble connection

superbubbleDr. Joanne Dawson
joanne.dawson@mq.edu.du - Macquarie University/CASS

Jill Rathborne
CASS

When the most massive stars end their lives, their supernova explosions blow enormous “superbubbles” in the interstellar medium, which may be thousands of light-years in diameter. These superbubbles sweep up material as they grow, until they are surrounded by thick skins of dense gas – the perfect environment for the condensation of new star-forming clouds. They may also grow vertically to expand right out of the plane of the Galaxy, venting their hot interior gas high above the Disk. This project will investigate ongoing star formation in dense clouds associated with Superbubbles in the Milky Way, and in particular those located far above the Galactic Plane where the star formation activity is usually low. The student will work with multi-wavelength data from radio to the infrared in order to build up a comprehensive picture of current and future star formation, including carrying out their own dedicated observing projects on sub-mm telescopes in the Atacama desert in Chile. The project may be developed in several directions, including collaboration with numerical modellers to study the dense cloud formation process, and expansion to the wider population of high-altitude clouds in the Milky Way.

2D spectroscopic analysis of local dwarf star-forming galaxies

2D SpecDr. Ángel López-Sánchez
- Macquarie University/AAO

The new observational technique of 2D spectroscopy using Integrated Field Units (IFU) is providing amazing new results about the kinematics and the chemical composition of galaxies. In particular, Blue Compact Dwarf Galaxies (BCDG) are excellent targets to perform such studies, because their modest sizes allow that all the galaxy can be observed in just some few pointings. During the last years we have collected some 2D spectroscopy data of a sample of BCDG using both the WiFeS instrument available at the 2.3m ANU telescope at Siding Spring Observatory and the SPIRAL instrument available at the 3.9m Anglo-Australian Telescope, also at Siding Spring Observatory. The preliminary analysis of these data are quite promising.

We are offering the opportunity of study a sample of several BCDG for which we already have good-quality data, as well as continue our observations of BCDG at these (WiFeS at 2.3m ANU and new instrument KOALA at 3.9m AAT) or other optical telescopes (GEMINI, VLT, WHT, CAHA).

In particular, this project will give the student a detailed understanding of the 2D spectroscopy techniques. The student will then gain expertise in the reduction and analysis of this kind of data. The aims of this project are to perform a detailed 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 ionized gas within these galaxies. The analysis of the stellar component underlying the strong starbursts can be also studies. Hence, we will compare the properties of the stars and the ionized gas with the properties of the neutral gas (derived using our own ATCA observations).

Finally, the student will also learn to write up the results not only for his/her Thesis but for subsequent publications. As an example of this project, please consult the 2D spectroscopical analysis of the brightest star-forming region of the local BCDG IC 10, López-Sánchez et al. (2011), and the combined optical-radio study of the BCDG NGC 5253, López-Sánchez et al. (2012).

Other Australian Astronomical Observatory Projects

2dFAAO staff

The Australian Astronomical Observatory (AAO) hosts research staff in areas of optical/infrared astronomy and instrumentation. Strong collaborative links exist between AAO and MQ AAAstro, including a number of joint staff positions between the institutes. PhD projects are available that can be jointly supervised by AAO staff and astronomers at AAAstro. Otherwise you can browse the research interests of AAO staff here

Please contact the relevant AAO staff person for arranging a suitable MQ supervisor for the project.

Other CSIRO Astronomy and Space Science Projects

SKACASS staff

The CSIRO Astronomy and Space Science (CASS) is the home for a number research staff in areas of radio astronomy and instrumentation. MQ AAAstro is in the process of establishing collaborative links with CASS staff and there are opportunities for joint PhD projects. CASS staff interests can be browsed here.

If you are interested, please follow the procedure here for arranging a MQ supervisor for the project.

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