PhD Projects 2018

Below is a list of PhD projects being offered in 2018. The list will be continuously updated over time.

Please click on a project title to expand it and find out more about it. The associated contact name refers to the first supervisor and forms the start of their email address, e.g. "Contact: Joe.Bloggs" refers to email address Joe.Bloggs@manchester.ac.uk.

You are welcome to contact a member of staff to find out more about their project. Alternatively, you are welcome to discuss other project ideas you may have.

  • C-Band All-Sky Survey - Understand the high-frequency radio sky

    Supervisors: Prof. Clive Dickinson, Dr. Paddy Leahy

    Contact: Clive.Dickinson

    Project Description: The C-Band All-Sky Survey (C-BASS) is a novel radio astronomy project to map the entire sky at 5 GHz on large scales in intensity and polarization. The final maps will be an important legacy survey for the entire astronomical community. The data will be used to study the diffuse Galactic emission such as supernova remnants and molecular clouds, as well as a vital foregrounds template for cosmology surveys. C-BASS data will be important for searching for gravitational waves from the early Universe using CMB polarization data, where foregrounds contaminate the weak cosmological signal. Observations are being made using two 5m class dishes, one located in northern California and one in the Karoo, South Africa. The northern survey is almost ready while the southern survey is just starting. The student will join the C-BASS team (in collaboration with Caltech, JPL, University of Oxford, and the University of Rhodes) to understand and calibrate the data and make the final maps. The data will then be used for a variety of scientific analyses before dissemination to the astronomical community.

  • Constraining the physics of the early Universe with the Simons Observatory

    Supervisor: Michael Brown

    Contact: M.L.Brown

    Project description: The Simons Observatory is a next generation Cosmic Microwave Background (CMB) telescope to be located in Chile. The Simons Observatory’s primary goal is to detect a very specific pattern in the polarisation of the CMB radiation (termed “B-modes”) which will provide a unique observational window into the very early Universe and physics at GUT-scale energies. As part of our group you will have the opportunity to get involved with this state-of-the-art CMB experiment in a number of areas including investigating the best scanning strategies to use when conducting the observations and developing sophisticated analysis techniques to extract the extremely faint B-mode signal from the experimental data. This project would suit a student with keen analytic and computational skills.

  • Understanding Dark Energy with weak lensing surveys

    Supervisor: Michael Brown

    Contact: M.L.Brown

    Project description: The JBCA cosmology group is leading the SuperCLASS survey on the e-MERLIN and Lovell telescopes located at Jodrell Bank. The primary goal of SuperCLASS is to develop the emerging field of weak lensing using radio telescopes and our group is leading this work for SuperCLASS. In particular, we are pioneering new weak lensing analysis techniques for radio interferometers and for measuring optical-radio cross-correlation weak lensing signals. Ultimately these techniques will be used to help understand the physics of Dark Energy using data from the Square Kilometre Array, both on its own and in cross-correlation with future optical surveys using the ground-based LSST and Euclid satellite experiments. This project would suit a student with keen analytic and computational skills.

  • Next Generation Hydrodynamic Simulations of Galaxy Clusters

    Supervisor: Scott Kay

    Contact: Scott.Kay

    Project description: Galaxy clusters are interesting objects to study for two reasons. Firstly, they teach us about galaxy formation: their extreme environment causes galaxies to evolve more rapidly than in the field, as gravitational and hydrodynamic processes strip off a galaxy’s gas supply and starve them of fuel for further star formation and black hole growth. Secondly, as the largest gravitationally bound objects in the Universe, the galaxy cluster distribution is a sensitive probe of dark matter and dark energy. As part of the international Virgo Consortium, we are leading a state-of-the-art cluster simulation project where we are now able to resolve the cluster galaxy population in detail. These simulations are currently being used to further our understanding of the above two topics. Over the next few years, the next generation of computing facilities will allow us to run these simulations with even more detail and thus allow us to improve the realism of our simulations further. The aim of this project will be for the student to participate in the development of these next-generation simulations, particularly improving the cluster physics modelling (e.g. star formation and feedback processes, hydrodynamics, magnetic fields) and testing the models against a wide range of multi-wavelength observational data. Example areas of study include the triggering of AGN and the interaction of their outflows with the hot intracluster gas, and how star formation in galaxies is affected they move through the cluster.

  • Beads on a String: The formation of massive stars by filamentary accretion

    Supervisor: Rowan Smith

    Contact: Rowan.Smith

    Project description: Observations by the Herschel space telescope have shown that molecular clouds, the stellar nurseries of our galaxy, are threaded by long filaments of dense molecular gas in which stars form at regular intervals like beads on a string. Understanding this process has important implications for all of astronomy, as the number and masses of stars formed in a galaxy will affect it’s evolution when the massive stars explode in supernovae explosions. Moreover, as planets form around stars, it will also affect the types of planetary systems that can be formed.

    This PhD project will use cutting edge numerical simulations of filamentary molecular clouds that include chemistry and magnetic fields to investigate to investigate such structures. We will investigate the formation of the filaments, and how they fragment into stars. In particular we will test how flows of mass along the filaments can lead to the formation of massive stars (greater than 8 solar masses) that will go supernovae when they die. A crucial part of the project will be to make critical comparison of the predictions of the above models with observational data in terms of observable quantities seen by instruments such as ALMA using post-process radiative transfer calculations. This means the student will learn to use both theoretical and observational techniques throughout their PhD thesis.

  • How do galaxies form stellar nurseries throughout cosmic time?

    Supervisor: Rowan Smith

    Contact: Rowan.Smith

    Project description: Stars form in dense clouds of molecular gas in galaxies, but how the formation of these clouds and the stars within them depend on conditions within the galaxy is still unknown. In spiral galaxies, are clouds formed in the dense spiral arms more efficient at making stars, than in regions between the arms? Are molecular clouds the same in small irregular galaxies dominated by supernovae as in spiral galaxies? How does all this change in starburst galaxies where there is more energetic feedback from the forming stars? These questions are particularly important for galaxies at earlier cosmic times which are likely to be quite different to our current Milky Way.

    In this project we will use ground-breaking high-resolution simulations of how molecular gas evolves in galaxies to answer these questions, and investigate how star formation may proceed in other galaxies beyond our Milky Way. We will vary quantities such as the galactic potential, gas surface density, stellar feedback and abundance of chemical coolants in the gas, to examine how star formation may differ in other environments such as those found at earlier cosmic times. For this project, previous experience of programming and running large simulations would be beneficial, but is not absolutely necessary as the student will learn the necessary techniques throughout the project.

  • What can we learn from future measurements of the Sunyaev-Zeldovich Effect?

    Supervisors: Jens Chluba and Scott Kay

    Contact: Jens.Chluba

    Project description: Clusters of galaxies are the largest collapsed structures in our Universe, typically hosting many hundreds of individual galaxies and being filled with a hot (several million degrees), X-ray emitting plasma. As such, clusters can be used to probe the formation and growth of structures at the largest cosmological scales. This allows one to constrain important cosmological parameters and answer equations about dark matter and dark energy, both mysterious substances that together are known to make up some ~94% of the energy density of our Universe.

    Clusters have been studied using optical and X-ray observations and many hundreds are now also detected through the so-called Sunyaev-Zeldovich (SZ) effect (e.g., using the Planck satellite). The SZ effect is caused by the up-scattering of photons from the cosmic microwave background (CMB) by the hot electron plasma residing inside galaxy clusters. Utilizing the SZ signal for cosmological studies requires understanding the relations of the signal to the underlying structure of the medium.

    In this PhD project, we will study what one can learn about the cosmological structure formation process by combining future SZ measurements with X-ray observations. High-resolution/sensitivity SZ observations will be carried out as part of the next steps in CMB cosmology (e.g., using CCAT-prime and Stage-IV CMB) and also new X-ray observations will become available soon (e.g., e-Rosita and Athena). This will open up many novel avenues for exciting studies of individual clusters and their role in cosmology, a broad topic that is targeted by this project.

  • Variability in Astrophysical Masers

    Supervisor: Malcolm Gray

    Contact: Malcolm.Gray

    Project description: Astrophysical masers are known to vary on timescales from minutes to decades,
    depending greatly on source type and molecular species. Most of this variability is of
    fairly low amplitude and/or slow. However, there are, in addition, flaring events, where
    the maser flux density, as measured by a single-dish radio telescope, changes by
    orders of magnitude on a timescale of typically days to months. Flares may be periodic,
    aperiodic or pseudo-periodic, and there is at least one example where flares in two
    different maser species, water and methanol, are coupled in a periodic, mutually
    exclusive flaring pattern. Long-term monitoring of two methanol maser frequencies
    by a single-dish radio telescope (Goedhart et al. 2004) has demonstrated the enormous
    variety of variability behaviour.

    A new 3D maser code will be applied to the flaring problem, to generate synthetic
    light curves that can be compared with observations. Likely scenarios that can be
    tested with the code are rotation of irregular objects, line-of-sight overlap of masing
    clouds, clusters of objects orbiting in discs, and maser sources pumped by periodic
    episodes of infra-red irradiation.

  • Computational Models of Astrophysical Masers

    Supervisor: Malcolm Gray

    Contact: Malcolm.Gray

    Project description: New interferometric instruments such as ALMA have enabled us to produce detailed
    images of masers in the 100-GHz to 1-THz region for the first time. Single-dish
    instruments, such as the aircraft-mounted SOFIA, are opening up an observing window at
    frequencies above 1-THz. We need computational models of methanol, ammonia,
    formaldehyde and water masers in star-forming regions, evolved stars and external
    galaxies to test our understanding of these new observations. The project
    involves two types of modelling: The first type is parameter-space searching, where
    the non-LTE radiative transfer problem is solved in a fairly straightforward model
    many times over a wide range of physical conditions. This allows us to identify the
    optimum conditions for amplification in the observed maser lines, and to select
    transitions for new observations by SOFIA. The second type of model involves more
    sophisticated simulation of specific sources, for example the red supergiant star VY
    CMa, which has now been imaged by ALMA in the 321, 325 and 658GHz water maser
    lines. Since the number of water maser lines comfortably exceeds the number of
    formal free parameters in the computer models, it may be possible to attempt the
    inverse problem for masers, where physical conditions are inferred from brightness
    ratios at the highest spatial resolutions, corresponding to co-propagation of masers at
    different frequencies.

  • Next-Gen modelling for high-precision exoplanet microlensing surveys

    Supervisor: Eamonn Kerins

    Contact: Eamonn.Kerins

    Project description: Galactic microlensing describes the small-scale distortion and magnification of starlight by foreground stars and planets in our Galaxy. It is a technique that is being used to detect cool, low-mass exoplanets. Such planets are predicted to remain at the orbital distances at which they form and so microlensing samples provide a direct probe of planet formation
    theories.

    Manchester is a World leader in the development of detailed microlensing models that predict the frequency, distribution and duration of microlensing events. Comparison of such models to large datasets allows us to probe the exoplanet occurrence rate, including the occurrence of planets unbound to a host star (so-called free-floating planets - or FFPs). The models also allow us to test the relative plausibility of multiple degenerate microlensing lightcurve fits to individual exoplanet candidates.

    A project is available for a student to further develop the Manchester-Besancon microlensing Simulator (MaBuls - www.mabuls.net). Possible developments and uses include:

    • the ability to provide predictions for simultaneous observations from ground- and space-based telescopes, which can facilitate direct mass measurements.
    • incorporation of additional Galactic physics such as improved models of the Galactc bulge, 3D extinction maps, the low-mass stellar mass function, stellar binarity.
    • detailed comparison with enlarged published microlensing datasets, as well as comparison of subsets exhibiting higher-order effects (finite source events, parallax/xallerap events, ...)
    • Galactic prior modeling of individual microlensing exoplanet canddates with degenerate lightcurve solutions.

    The project will involve substantial programming in Python and the use of state-of-the-art (and continuously evolving) Galaxy simulation models.

  • Studying Large-Scale Structure using Intensity Mapping of CO at High Redshifts

    Supervisors: Clive Dickinson and Stuart Harper

    Contact: Clive.Dickinson

    Project description: Intensity mapping is a recently proposed method of efficiently mapping the emission of single spectral lines across cosmological volumes. Proposals for intensity mapping have been made using many different species such as atomic HI, CII, Lyman-N1, CO, amongst others. All the lines can be used to study the large-scale structures of galaxies and clusters, which trace the evolution of the baryonic matter density and cosmic expansion. As CO is predominantly found within the dark, cold cores of star forming nebulae, CO predominantly traces star forming galaxies, which means it can also be used to measure the star formation history of the Universe.

    The CO intensity mapping experiment called COMAP is planning to use the intensity mapping technique to map out a large volume of the Universe. The pathfinder instrument with 19 detectors is currently being constructed and commissioned at the Owens Valley Radio Observatory (OVRO) in California and should be making regular observations in 2018. COMAP will probe the redshift range of 2 < z < 3, which is during the epoch of peak of cosmic star formation. However, measuring the cosmological CO signal is expected to be challenging due to mixing of the signal with bright Galactic emission, turbulence within the atmosphere, instabilities of the instrumentation and the interaction of optical systems with the sky and surrounding environment. To overcome these challenges has required building a detailed end-to-end simulation of the COMAP experiment.

    The student will be involved in COMAP experiment, which is an international collaboration between Manchester, Caltech, JPL, Stanford, and Oslo. The project offers an opportunity to become involved in an exciting field of cosmological research that is still in its infancy. The thrust of the project will be to run simulations of the COMAP observations that will be critical in determining the specifications of the instrumentation and designing data analysis methods for recovering the cosmological CO signal. As such, the project offers a lot freedom in the topic or topics the student wishes to pursue, from instrumentation, atmospheric science, Galactic emission, cosmology, and advanced data analysis methods; depending on interest and experience of the student.

  • Receiver cryogenics development for the Simons Observatory

    Supervisor: Lucio Piccirillo

    Contact: Lucio.Piccirillo

    Project description: The Simons Observatory (SO) is a forthcoming project to measure the polarization of the Cosmic Microwave Background with unprecedented sensitivity. The principal science goal is measurement of the B-mode polarization anisotropy which, at large angular scales, would constitute direct evidence for inflation. SO will be comprised of two main elements, a six-meter aperture telescope and a series of half-meter aperture cameras. The unique combination of large and small apertures will allow SO to cover a wide range of angular scales.

    Manchester is heavily involved in the SO collaboration, particularly in cryogenic and thermo-optical design of the LATR receiver. This receiver is coupled to the SO 6 m cross-Dragone telescope and will be approximately 2.4 m in diameter, greater than 2 m in length, weigh over 3 metric tons, and have five cryogenic stages (80 K, 40 K, 4 K, 1 K and 100 mK). The LATR is coupled to the telescope via 13 independent optics tubes containing cryogenic optical elements and over 20000 detectors. Given the size and complexity of the receiver, cryogenic design is exceptionally challenging.

    The student will be heavily involved in the cryogenic and thermo-optical design, modelling, development, realisation and experimental testing of the LATR receiver.

  • ▲ Up to the top