PhD projects 2016

PhD projects offered for starting in 2016 are listed below. Click on the project title to see details of the project. You are encouraged to directly email the project supervisor to discuss it with them.

If you have ideas of your own for potential projects then please contact either a member of staff working within the relevant research area or else email the JBCA PhD admissions officer, Dr Michael Keith (Michael.Keith@manchester.ac.uk) who can put you in contact with a member of staff.

  • Searching for pulsars and fast transients with MeerKAT
    Supervisor Prof Ben Stappers | Ben.Stappers@manchester.ac.uk
    Co-supervisor Dr Michael Keith | Michael.Keith@manchester.ac.uk
    Research type
    • Observational
    Research areas
    • Pulsars, neutron stars and transients
    • Astronomical instrumentation and technology (inc SKA)
    Funding SRFC
    Project Description

    Radio pulsars are some of the most extreme objects in the known Universe. They have masses of about 1.4 times that of our Sun, radii of about 10 km and they spin at up to 700 times per second. Amongst other things these objects can tell us about the physics of their spin and their extremely strong magnetic fields. They can also be used as tools with which to test the laws of physics including testing theories of gravity and allowing direct detection of gravitational waves. We are about to begin a survey for new radio pulsars and fast transients using a next generation radio telescope called MeerKAT. This array of telescopes, located in South Africa, operates at frequencies around 1500 MHz and is giving us a completely new view of the radio pulsar population.

    This project would involve the student becoming involved in the search team and hunting for new pulsars and fast transients. The new discoveries will be fully characterised by the student in order to understand them, thereby revealing if any of them are useful for further physical tests. The results of the survey will also be used to study the nature of the population of radio pulsars. We will be targetting globular clusters and interesting point sources with a chance of finding new and interesting systems. MeerKAT pulsar surveys are a stepping stone on the road to searching for pulsars with the Square Kilometre Array (SKA).

  • Galactic Foregrounds and their relevance to the Cosmic Microwave Background
    Supervisor Prof Richard Davis | richard.j.davis@manchester.ac.uk
    Co-supervisor Prof Clive Dickinson | Clive.Dickinson@manchester.ac.uk
    Research type
    • Observational
    Research areas
    • Cosmology and the early Universe
    • Other
    Funding SRFC

    As has been shown the BICEP work is controlled by our understanding of the Galactic Foregrounds and particularly in polarisation. We are currently studying the synchrotron radiation with the CBASS project and free-free emission with Hbeta off the Plane and RRLs on the Plane. Dust comes in at least two forms of thermal and anomalous forms and is studied with high frequencies for thermal dust and Ka band for the anomalous dust.

  • Supernovae and starformation in the Starburst galaxy M82
    Supervisor Dr Thomas Muxlow | tom.muxlow@manchester.ac.uk
    Co-supervisors Dr Robert Beswick | Robert.Beswick@manchester.ac.uk 
    Dr Megan Argo | mkargo@manchester.ac.uk
    Research type
    • Observational
    Research areas
    • Pulsars, neutron stars and transients
    • Birth, evolution and death of stars
    • Astrophysical dust and gas
    • Formation and evolution of galaxies and clusters
    • Other
    Funding SRFC

    Starburst galaxies exhibit high rates of star-formation and are responsible for a large fraction of the massive stars formed in the local Universe. Within each of these star-forming galaxies, massive stars quickly evolve to produce significant populations of supernovae and supernova remnants, which can be used to probe the ongoing star-formation rate, supernovae astrophysics and the ISM environment. Whilst significant star-formation occurs in the centre of these galaxies, the high level of dust and gas obscures much of this star-formation from view.

    This project will use new state-of-the-art, very high resolution, radio observations to provide an unobscured view of the compact radio emission arising from this ongoing star-formation. Using one of the world's most powerful radio telescopes (e-MERLIN), extremely sensitive observations of the nearby, prototypical starburst galaxy M82 have been made, revealing more than 100 radio supernova remnants, compact HII regions, new supernovae and more mysterious objects that are yet to be classified. This project will utilise these new observations to study the population of compact radio sources in order to enhance our understanding of the star-formation process and evolution of supernovae and their remnants. In addition, deep radio imaging has been demonstrated to reveal an unexpected population of compact sources in M82 whose properties we are only beginning to understand.

  • First observations of the Galaxy with the Manchester-Athens Wide-Field Camera (MAWFC)
    Supervisor Prof Clive Dickinson | Clive.Dickinson@manchester.ac.uk
    Co-supervisors Dr Myfanwy Lloyd | myfanwy.lloyd@manchester.ac.uk
    Prof John Meaburn | john.meaburn@manchester.ac.uk 
    Dr Boumis Panayotis (National Observatory of Athens) | ptb@noa.gr
    Research types
    • Observational
    • Experimental
    Research areas
    • Birth, evolution and death of stars
    • Astrophysical dust and gas
    • Cosmology
    • Astrophysical instrumentation/technology
    Funding SRFC
    Other
    Project Description

    The Manchester-Athens Wide Field Camera (MAWFC) is a new instrument to map out large-scale line emission with arcmin resolution and a 30 degree field-of-view. The instrument was designed by Prof John Meaburn and recently built in Athens, by a team led by Dr P Boumis. The instrument was designed to map line emission from various optical species (eg hydrogen, nitrogen, sulphur, oxygen) with a sensitivity limited by background light. Being portable, it can be moved to different observing sites and, in principle, can deliver a full-sky survey in multiple emission lines. Commissioning and testing of the instrument is currently underway and science observations are expected to begin in 2016. The student will spend a significant fraction of time in Greece, working with Dr Boumis and his team, particularly in the 1st year, to ensure the instrument is working to its full capability and to perform observations. First observations will be of known features of the sky, including the Eridanus loops, discovered by Prof John Meaburn in Manchester (1965). The student will also be involved in designing and carrying out the all-sky survey of Halpha and Hbeta, and in interpreting the first results of this large survey. The survey will be useful for studying the interstellar medium, warm ionised gas, molecular clouds and supernova remnants to name just a few, as well as a template for free-free emission for cosmic microwave background experiments.

  • Computational Models of Astrophysical Masers
    Supervisor Dr Malcolm Gray | Malcolm.Gray@manchester.ac.uk
    Co-supervisor Dr Anita Richards | a.m.s.richards@manchester.ac.uk
    Research types
    • Observational
    • High Performance Computing
    Research areas
    • Birth, evolution and death of stars
    • Astrophysical dust and gas
    Funding SRFC
    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 airborne 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 radiativ e 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.

  • The Physical Nature of Masing Objects
    Supervisor Dr Malcolm Gray | Malcolm.Gray@manchester.ac.uk
    Research types
    • Birth, evolution and death of stars
    • Astropyhsical dust and gas
    Funding SRFC
    Project Description

    Astrophysical masers are generated in a variety of sources, varying in scale from comets in our own Solar System, to kiloparsec-scale zones in the cores of certain active galaxies. A common feature of most maser sources is that the emitting regions are observed as a set of discrete features, some of which are resolved at VLBI resolution, that are distributed across all, or only part, of a much larger source. The purpose of the project is to attempt to determine, through analysis of observational data and computer modelling, what the physical nature of the maser features is. There could be several answers, depending on the type of source. Are comets the hosts of masers in star-forming regions, as they are in our Solar System, for example? What is it that makes the gas in maser features able to support population inversion and generate maser radiation, whilst presumably similar gas near to them apparently cannot? Recent data from space VLBI (baseline of 3 Earth diameters) has revealed structure smaller than 1 million km in water masers, helping to eliminate some possibilities.

  • Radiative Transfer of Radiation with OAM
    Supervisor Dr Malcolm Gray | Malcolm.Gray@manchester.ac.uk
    Research type
    • Theoretical
    Research area
    • Astropyhsical dust and gas
    Funding SRFC
    Project Description

    Radiation with orbital angular momentum (OAM), as opposed to the spin angular momentum (SAM) associated with polarization, may be routinely generated in the laboratory. Methods mostly include the insertion of a special phase-modifying component into a laser beam. Radiation with OAM has a number of unusual features: the instantaneous Poynting vector is not parallel to the direction of propagation, about which it traces a helical path; there is a component of the electric field in the direction of propagation and an infinite number of quanta of OAM may (in principle) be applied. Radiation with OAM has yet to be detected from an astrophysical source, though there is strong evidence that it is added to astrophysical signals by atmospheric turbulence. The project is to consider the transfer of radiation with OAM, and, in particular, its generation by:

    1. turbulent velocity fields, where the local gradient of the refractive index may be very high;
    2. regions of organized but inhomogeneous magnetic fields, and
    3. by locally intense gravitational fields.
  • Very High-Frequency Resolution Observations of Masers
    Supervisor Dr Malcolm Gray | Malcolm.Gray@manchester.ac.uk
    Funding SRFC
    Project Description

    A new generation of radio interferometers, including e-MERLIN at Jodrell Bank, and the JVLA, has correlators that are highly flexible in the arrangement of the frequency channels, of which there are typically tens to hundreds of thousands. These instruments have the capability to observe spectral lines with a resolution as fine as 1Hz, or slightly better. In the case of maser lines, such resolution offers the possibility of investigating some fundamental properties of astrophysical maser radiation. Do astrophysical masers have radiation statistics that depart from the Gaussian form that holds for thermal radiation, for example? In the case of highly-evolved giant stars, the high resolution may be used to detect correlated frequency shifts between a number of separate maser features, enabling us to detect the passage of acoustic and MHD waves through the circumstellar envelope: a form of circumstellar seismology that has not been previously attempted. e-MERLIN time has already been awarded to obtain the first data for this project, and observations will commence when the recirculation system in the correlator has been completed and tested.

  • Towards precision mass measurements of cool exoplanets using microlensing
    Supervisor Dr Eamonn Kerins | Eamonn.Kerins@manchester.ac.uk
    Research types
    • Observational
    • Theoretical
    Research areas
    • Exoplanets
    • Gravitational microlensing
    Funding SRFC
    Project Description

    Microlensing, which employs the principles of gravitational lensing, is the only current technique able to discover cool low-mass (below 30 Earth mass) exoplanets that lie beyond a few AU from their host. Planet formation theories suggests that low mass planets in this region may not have migrated far since their formation. Therefore, understanding the demographics of these system can allow us to directly test planet formation theories.

    Previous evidence from near-IR observations of open clusters and tentative data from ground-based microlensing surveys hint at a potentially large population of planets isolated from any host star (so-called free floating planets). Small planets (eg similar to Earth) could become unbound as a result of ejection during the planet formation stage. On the other hand a large abundance of massive free-floating planets (ie Jupiter-like) would suggest that they must form in isolation from a stellar host. Current data tentatively hints at the latter scenario but a larger dataset is badly needed.

    The following projects involve the use of the newly develped Manchester-Besancon Microlensing Simulator (MaBulS), which is available online at www.mabuls.net. The simulator is the most advanced of its kind in the World and the projects below will extend its capabilities to allow its use for real-time modeling of bound exoplanet candidates and for assessing the abundance of free-floating planets.

    A) Real time microlensing modeling

    Manchester has developed a real-time microlensing simulator (MaBulS - www.mabuls.net) which we would like to extend to provide real-time modelling constraints for ongoing microlensing events. We participate in the MiNDSTEp microlensing follow-up team which performs lucky imaging photometry using the Danish 1.54m Telescope at La Silla, Chile. One available project is to extend MaBulS to provide real-time information on the microlensing lens and source properties based upon the observed location, timescale and brightness of ongoing events. Additional information such as the source angular size and lens-source proper motion can also be modeled and can be used to provide more detailed mass modeling of the lens system. At any given time there are always many ongoing events so the observations need to prioritise the most promising systems. We intend to use the MaBulS real-time system to inform the ongoing observation strategy, leading to improved observing efficiency across all ongoing event. This project will also include opportunities to contribute to the MiNDSTEp observing effort through both remote observing and on-site observing at the Danish Telescope at the ESO La Silla Observatory, which is located at the edge of the Atacama desert in Chile.

    B) Precision planet mass measurements from Near-IR observations of Kepler2 microlensing events

    The second phase of the NASA Kepler mission (dubbed K2) will be making high time-resolution observations of the Galactic bulge from April-July 2016, and also towards the end of 2016. The principal aim of these observations will be to look for free-floating planets. Several ground-based observatories will also monitor the same events, including the near-infrared VVV survey in which Manchester has strong involvement. The baseline between Kepler and Earth should give rise to observable parallax effects in the microlensing signatures which, coupled with near-IR observations, should allow, for the first time, direct mass measurements of free floating planets. Comparison of the observations with detailed simulations will allow limits to be placed on their abundance. This PhD project involves developing the MaBulS simulator to enable its use for statistics of free-floating planets, and to apply it to the K2 sample to make an assessment of the free-floating planet abundance.

  • Data mining the Galactic Centre: the near-infrared VVV survey
    Supervisor Dr Eamonn Kerins | Eamonn.Kerins@manchester.ac.uk
    Research types
    • Observational
    • Theoretical
    Research areas
    • Transients/Time-domain Astrophysics
    • Gravitational microlensing
    Funding SRFC
    Project Description

    The Vista Variables in the Via Lactea (VVV) survey is a multi-year survey of the inner Galaxy at near-infrared wavelengths using VISTA, the World's largest infrared telescope.

    The VVV survey team is an international collaboration of European and Chilean astronomers. At Manchester our contribution to the project has been the development of a difference image analysis pipeline which can identify millions of variable objects from around 3 million images of around 100 million monitored stars. The key goals of the survey include:

    • the identification of "standard candle" variable populations such as RR Lyrae stars, which can be used to develop a 3D reconstruction of visible stars in the inner Galaxy;
    • the detection of rare gravitational microlensing events which allow us to determine the underlying mass distribution of the inner Galaxy;
    • the identification of stellar motions on the sky (proper motion) which allow us to measure the kinematical properties of the inner Galaxy.

    This PhD project will involve working on one or more of the following areas:

    1. The development of automated classification schemes for cataloguing different classes of variable and transient objects.
    2. The development of a "citizen-science" front-end to allow public users to engage in classifying objects or finding specific classes of objects of interest.
    3. Mapping the underlying distribution of RR Lyrae stars, Young Stellar Objects (YSOs), novae, and/or gravitational microlensing events, including a careful assessment of detection biases.
    4. Detecting stellar proper motions and using this to constrain the kinematics of the inner Galaxy.

    This project will involve a significant element of computation and software development in Python. Knowledge of Python is not a prerequisite, though a willingness to learn it is, as is a keen aptitude for programming. It is also anticipated that the student will present their work both at conferences and/or at VVV collaboration meetings in Europe and in Chile.

  • Magnetic fields around Radio Galaxies
    Supervisor Dr Anna Scaife | anna.scaife@manchester.ac.uk
    Co-supervisor Dr Patrick Leahy | j.p.leahy@manchester.ac.uk
    Funding SRFC
    Project Description

    Faraday rotation maps of individual radio galaxies probe the magnetic field pattern in the gas surrounding the radio lobes, typically the atmosphere of a group or cluster of galaxies. Only a few dozen objects have been mapped so far in detail but the results are already puzzling. A number of objects show a strong "banding" pattern (e.g. Guidetti et al 2011) which is difficult to explain in terms of current models for the magnetic fields in clusters. It is not even clear whether this structure is induced by the expansion of the radio lobe bubbles, or is tracing general magnetic field in the cluster. The POSSUM-12 suvey is one of the Early Science projects for ASKAP, the Australian Square Kilometre Array Pathfinder. In 2016-17 it will observe a large sky area (about 780 square degrees) over a very wide bandwidth, 700-1800 MHz in full polarimetry, which is ideal for making Faraday rotation maps. The survey will detect many thousands of sources, mostly unresolved. However, we expect a few dozen nearby and giant radio galaxies to be resolved enough to allow RM mapping. In this project the student will search such for objects in the survey and analyse the Faraday data to help understand the magnetic field structure in clusters of galaxies.

  • Exploiting Phased Array Feeds for the Lovell and eMerlin
    Supervisor Dr Michael Keith | Michael.Keith@manchester.ac.uk
    Research types
    • Experimental
    • Computational
    Research areas
    • Technology development
    • Pulsars
    • Transients
    • Others, depending on interests
    Funding SRFC
    Project Description

    Full project description coming soon.

  • Advanced study of giant pulsar timing archives
    Supervisor Dr Michael Keith | Michael.Keith@manchester.ac.uk
    Research types
    • Computational
    • Data science
    Research areas
    • Pulsars
    • Cloud computing
    Funding SRFC
    Project Description

    Full project description coming soon.

  • Ultra-precision pulsar timing for gravitational wave experiments
    Supervisor Dr Michael Keith | Michael.Keith@manchester.ac.uk
    Research types
    • Observational
    Research area
    • Pulsars
    Funding SRFC
    Project Description

    Full project description coming soon.

  • Fueling star-formation and accretion in Galaxies - tracing dense, molecular gas
    Supervisor Dr Robert Beswick | Robert.Beswick@manchester.ac.uk
    Co-supervisor Dr Megan Argo | mkargo@manchester.ac.uk
    Prof Gary Fuller | gary.a.fuller@manchester.ac.uk
    Research type
    • Observational
    Research areas
    • Birth, evolution and death of stars
    • Astrophysical dust and gas
    • Formation and evolution of galaxies and clusters
    • Astronomical instrumentation and technology
    Funding SRFC
    Project Description

    Much of the star-formation underway in local galaxies resides in dust and gas rich galaxies with high levels of optical obscuration. These galaxies, often dubbed Starbursts, exhibit high rates of star-formation and are responsible for a large fraction of the massive stars formed in the local Universe. Within each of these star-forming galaxies, dense regions of gas and dust form massive stars which quickly evolve to produce significant populations of supernovae and supernova remnants. These stellar end-points can then be used to probe the ongoing star-formation rate, supernovae astrophysics and the ISM environment. However critical questions remain regarding the environment where this heightened star-formation occurs, and the affects on the gas in galaxies of the ongoing star-formation and accretion processes.

    This project will utilize new state-of-the-art observations with radio interferometers including e-MERLIN (http://www.e-merlin.ac.uk) and the JVLA (http://www.nrao.edu/vla) to observe the fuel of these star-formation and accretion activities seen in galaxies. These new radio wavelength observations include faint dense molecular gas tracers, such as OH, HCN, HCO+, as well as the neutral hydrogen and provide a high angular resolution view of the dense gas in nearby active galaxies (both starbursts and Active Galactic Nuclei). Using these observations this project will investigate the dense gas properties of the central regions of these sources. This will be combined with deep radio continuum observations of these sources charting the star-formation and accretion processes themselves, and thus the project will allow an obscuration free view of both the causes (fuel - dense gas) and consequences of star-formation and accretion within galaxies.

  • Transmission spectroscopy of exoplanet atmospheres
    Supervisor Dr Eamonn Kerins | Eamonn.Kerins@manchester.ac.uk
    Research types
    • Observational
    • Theoretical
    Research area
    • Exoplanets
    Funding SRFC
    Project Description

    We are entering a new era of exoplanet characterisation thanks to the large numbers of hot exoplanets (those orbiting close to their hosts) which have been routinely discovered by ground and space-based transit surveys such as SuperWASP, HAT and Kepler. Transmission spectroscopy is a highly successful technique for probing the atmospheres of hot exoplanets. This technique will be used more frequently as the samples of known nearby planets rapidly expands with the advent of surveys such as NGTS and the launch of the NASA TESS mission in 2017 and the ESA PLATO mission in 2026, both of which will detect relatively nearby exoplanets using the transit method.

    Manchester has developed a transmission spectroscopy program in collaboration with colleagues at NARIT in Thailand. We have been very sucessful in gaining observing time on the ULTRASPEC instrument on the 2.4m Thai National Telescope (TNT). ULTRASPEC is a high speed optical photometer which allows high time resolution observations of exoplanet transits. By observing the wavelength-dependent nature of the transit profiles we are able to constrain the atmospheric chemical composition of hot exoplanets down to the mass of Uranus.

    With strong exoplanet research links being fostered between Manchester and NARIT we are looking to expand this program. A PhD project is available for a student to work on transmission spectroscopy. The student will be involved in the following areas:

    1. selection of exoplanet targets for transmission spectroscopy observations with TNT and other facilities
    2. help with the preparation of observing proposals to TNT and other facilities
    3. data reduction and analysis of transit lightcurves using an exisiting pipeline developed at Manchester.
    4. comparison of multi-wavelength transit curves with exoplanet atmospheric models.

    Additionally, the project will involve the development of automated criteria for the selection of transmission spectroscopy targets, in preparation for anticipated large potential target catalogues which will come from the NASA TESS mission from 2017.

  • Planetary nebulae in the Milky Way Bulge
    Supervisor Prof Albert Zijlstra | albert.zijlstra@manchester.ac.uk
    Research type
    • Observational
    Funding SRFC
    Project Description

    Planetary nebulae form when a dying star ejects it outer envelope, returning between 40% and 80% of its mass into space. Planetary nebulae are bright, making then ideal to study distant stellar populations. We have started a project to study planetary nebulae in the Galactic Bulge, the least understood of the components of the Milky Way. The age of the Bulge is an area of controversy: while some studies find that it is among the oldest parts of the Milky way, other studies find significant poulations of younger stars. The student will be in charge of a project to derive elemental abundances and stellar masses from optical spectra of around 100 planetary nebulae, acquired with the ESO Very Large Telescope. This will be used to study star formation history, and the chemical enrichment history of the Bulge. The project can involve an extended stay at the University of Hong Kong, depending on the preference of the student.

  • Stars through the eyes of SPHERE
    Supervisor Prof Albert Zijlstra | albert.zijlstra@manchester.ac.uk
    Research type
    • Observational
    Funding SRFC
    Project Description

    SPHERE is a new instrument on the 8-meter Very Large Telescope. With its extreme adaptive optics system, it provides the sharpest images ever obtained with resolutions down to 10 milli-arcsec. It has recently taken the first direct imaging of the photosphere of a star other than the sun, Betelgeuse. Sphere is used to map the outflows from evolved stars, which are in the end phase of their evolution when stars lose over half their mass through a superwind. It is finding spectacular shapes, ranging from precessing jets to dense tori, putting into severe question the common assumption that the winds are spherically symmetric. Binary companions are likely a major cause of the asymmetries. We are looking for a PhD student to analyse new Sphere data on these stars, as part of the "Other science" guaranteed time observations which is led by the Lagrange Department in Nice). The project will involve observations and radiative transfer modeling, including polarisation. Up to half the time may be spend at Nice, under the STFC Long Term Attachment program.

  • Source sample classification and redshift information strategies for cosmology with radio weak lensing surveys
    Supervisor Prof Michael Brown | m.l.brown@manchester.ac.uk
    Co-supervisor Dr Ian Harrison | ian.harrison-2@manchester.ac.uk
    Research types
    • Observational
    • Theoretical
    Research areas
    • Cosmology and the early Universe
    • Gravitational weak lensing
    • Formation and evolution of galaxies and clusters
    Funding SRFC
    Project Description

    Measuring the weak lensing distortion of the shapes of millions of galaxies across the sky is an excellent way to learn about cosmological parameters and probe the different physical models of Dark Energy. Most weak lensing studies (such as the Dark Energy Survey) are conducted with optical telescopes, but recently new work has begun to focus on the prospect of weak lensing with radio telescopes such as e-MERLIN and the Square Kilometre Array (SKA). Doing weak lensing at radio wavelengths has a number of advantages but also a number of new challenges, some of which will be addressed in this project:

    1. Contamination of Active Galactic Nuclei (AGN). The presence of AGN mistakenly included in the weak lensing sample of star-forming galaxies can cause an error known as 'model bias' which directly affects the cosmological results. The student will conduct studies into minimising the effect of AGN contamination, both modelling their shapes and working on classification strategies for using multi-wavelength data to identify them and remove them from the sample.
    2. Redshift follow-up strategies. The presence of redshift information for tomographic and 3D weak lensing will be another key component of radio weak lensing surveys. The student will explore ways to obtain redshift information for the radio weak lensing sources, using novel sub-threshold techniques, simulations and archival data.

    This project will be a mixture of computational and theoretical work, with a strong focus on statistical methods. As well as developing the methods on simulations, the student will also have opportunities to apply them to real data from eg the SuperCLASS and CHILES-con-pol surveys.

  • Magnetic reconnection and heating the solar corona
    Supervisor Prof Philippa Browning | philippa.browning@manchester.ac.uk
    Research type
    • Theoretical
    Funding SRFC
    Project Description

    Research in solar plasma physics is concerned with modelling the complex interactions of magnetic field with plasma in the solar atmosphere, in the context of the wealth of new space and ground-based observations of the Sun which is transforming our understanding of our nearest star. There are many synergies with the physics of magnetically-confined fusion plasmas, and there may be opportunities for PhD projects to explore both fusion and solar applications. A major unsolved problem is to explain why the solar corona is at a temperature of over a million degrees Kelvin (compared with a surface temperature of about 6000 K). Coronal plasma is believed to be heated by dissipation of stored magnetic energy, but the details remain controversial. A strong candidate for an efficient energy dissipation mechanism is the process of magnetic reconnection - which also operates in solar flares, and in many other space and astrophysical plasmas. PhD projects are available to model coronal heating through reconnection, both using numerical magnetohydrodynamic simulations and through semi-analytical modelling, based on the idea that the coronal field relaxes towards a minimum energy state. Current models of energy release in unstable twisted coronal loops will be extended to more complex configurations, investigating the multi-thread nature of coronal loops and interactions between different loops. One approach will be to complement results from two-fluid simulations by developing a relaxation model appropriate for Hall magnetohydrodynamics.

  • The origin of solar flare energetic particles and their observational signatures
    Supervisor Prof Philippa Browning | philippa.browning@manchester.ac.uk
    Research type
    • Theoretical
    Funding SRFC
    Project Description

    Solar flares are dramatic releases of stored magnetic energy in the solar corona. They are manifestations of the fundamental plasma physics process 'magnetic reconnection', which occurs in many other space and astrophysical contexts as well as in fusion plasmas. A challenging question is to understand how the magnetic energy is released and charged particles are accelerated to high energies in flares. We have been developing test particle models to show how particles can be accelerated in complex fields, both with fragmented current sheets and near magnetic null points. PhD projects are available to investigate particle acceleration and magnetic reconnection in solar flares, extending current models to incorporate the effect of the feedback of the accelerated charged particles on the electromagnetic fields, and investigating more realistic field configurations. Students may use a new 'reduced kinetics' approach to develop self-consistent models including energetic electrons and evolving magnetic fields. This work mainly relies on computer simulation, and may involve both the use of existing codes as well as code development. An important aspect of this work is 'forward modelling' of the observational signatures - the energetic particles may be detected both through hard X-ray and radio emission.

  • The Dark Energy Survey
    Supervisor Prof Sarah Bridle | sarah.bridle@manchester.ac.uk
    Co-supervisor Dr Joseph Zuntz | joseph.zuntz@manchester.ac.uk
    Research types
    • Observational
    • High performance computing (optional)
    Research areas
    • Cosmology and the early Universe
    • Gravitational lensing/microlensing
    Funding SRFC
    Project Description

    We are now analyzing the first year of data taken with the Dark Energy Survey (DES), which will make precise measurements of 300 million galaxies over 5 years of observations. Bridle is co-coordinator of the DES Weak Lensing Working Group and this project will focus on aspects of weak gravitational lensing critical to measuring cosmology from DES. The details of the project will depend on the interests of the student. Optional examples include:

    1. the high performance computing challenge of measuring shapes of 300 million galaxies from tens of images of each galaxy, with code that takes seconds to run per galaxy
    2. disentangling the effect of astrophysical alignments between galaxies from the cosmological effect of gravitational lensing
    3. developing the CosmoSIS software framework to collaboratively measure the equation of state of dark energy from multiple different types of observation.
  • Finding "black widows" and "redbacks" in the VVV survey
    Supervisor Dr Rene Breton | rene.breton@manchester.ac.uk
    Co-supervisor Dr Eamonn Kerins | Eamonn.Kerins@manchester.ac.uk
    Research types
    • Observational
    • Theoretical
    Research areas
    • Pulsars, neutron stars and transients
    Funding SRFC
    Project Description

    A large fraction of the fastest known spinning pulsars are found in compact binary systems with irradiated low-mass companions called 'black widows' and 'redbacks'. These binaries are named after deadly spiders because of the energetic pulsar hosts ablating their companions, a process which might eventually destroy them completely. Two recent discoveries make these systems very important to study:

    1. they appear to harbour unusually massive neutron stars, and
    2. some of them display reversible 'state transitions' marked by the appearance of an accretion disk and the disappearance of the radio pulsar

    The first discovery makes 'redbacks' and 'black widows' a perfect place to determine the mass boundary between neutron stars and black holes, while the second one implies that they represent a key stage of binary evolution that has yet to be understood.

    This PhD project will look into the development of a new approach to finding 'black widows' and 'redbacks' in order to circumvent the bias against detecting them in radio surveys due to the fact that they are eclipsing systems. This novel technique relies on the identification of the companion's optical counterpart in wide-field survey data using the characteristic colour and flux variability that they display on the orbital timescale of the system. The successful candidate will write a pipeline to mine archival survey data as well as analyse the upcoming 2nd generation VVV near-infrared survey of the Galactic bulge. Simulations of expected light curves will be made in order to derive selection criteria for candidate 'black widows' and 'redbacks' and follow-up optical and radio observation will be performed in order to confirm the new findings.

  • Observations and modelling of radio gravitational lens systems
    Supervisor Dr Neal Jackson | neal.jackson@manchester.ac.uk
    Research types
    • Observation
    • Data reduction
    • Computer modelling
    Research area
    • Gravitational lensing
    Funding SRFC
    Project Description

    Gravitational lenses are important because they give information about the mass distributions of lensing galaxies independent of their emission of light. We currently have an e-MERLIN legacy programme which aims to examine the central regions of lens galaxies (within 10-100pc of the central black hole) by studying the very faint lensed images of background sources which form close to the centres of lens systems. Lenses are also important because they function as natural magnifying glasses, allowing us to see background objects which would otherwise only be accessible to much larger telescopes. We are particularly interested in using these to study the radio properties of radio-quiet quasars, and determine the physical origin. Finally, we are involved in technical developments relevant to lens searches, such as calibration methods for the long baselines of the LOFAR telescope.

  • Dark Energy and Modified Gravity
    Supervisor Prof Richard Battye | Richard.Battye@manchester.ac.uk
    Co-supervisor Dr Francesco Pace | francesco.pace@manchester.ac.uk
    Research type
    • Theoretical
    Research area
    • Cosmology
    Funding SRFC
    Project Description

    The origin of the cosmic acceleration is one of the most significant unsolved problems in cosmology. The most simple explanation, a cosmological constant, is not compatible with our present understanding of particle physics, but none of the thousands of models that have been suggested are compelling. For a number of years we have been developing a phenomenology approach to dark energy and modified gravity and this project will be to continue this work. The key question is how can we extend the ideas of General Relativity in a systematic but conceptually simple way.

  • Techniques for Radio Weak Lensing
    Supervisor Prof Richard Battye | Richard.Battye@manchester.ac.uk
    Co-supervisor Prof Michael Brown | m.l.brown@manchester.ac.uk
    Research types
    • Observational
    • Data reduction
    • Computer modeling
    Research area
    • Cosmology
    Funding SRFC
    Project Description

    Weak lensing using Radio Observations will be competitive with those done in the optical when the SKA comes online - within the next ten years. Observations in the radio will have a number of advantages. However, much development work needs to take place to bring this to fruition. In this project will work on the following aspects:

    1. using radio observations to extract intrinsic alignments from higher signal-to-noise optical observations possibly using observations the SuperCLASS survey which is currently underway;
    2. using 21cm observations of the galaxies intrinsic shape to extract intrinsic alignment information;
    3. extracting the rotation measures from polarised radio observations.
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