XClose

UCL Department of Space and Climate Physics

Home
Menu

STFC PhD Projects 2019

Applications of STFC funded studentships at MSSL starting in 2019 are now open. PhD projects in astrophysics, planetary science and space plasma/solar physics are detailed below.

Applications submitted by 3rd February 2019 will be given full consideration. We will continue accepting applications until all places are filled. After we receive your application, we will select candidates for interviews. If you are selected, you will be invited for an interview at MSSL. You will have the opportunity to see the laboratory, students' flats and talk to current students. The studentships are for the advertised projects only. In your application, please specify which project you want to apply for. 

Entry requirements

An upper second-class Bachelor’s degree, or a second-class Bachelor’s degree together with a Master's degree from a UK university in a relevant subject, or an equivalent overseas qualification.

Students from the UK or those from the EU who meet the residency requirements (3 years' full-time residency in the UK) are potentially eligible for a Science and Technology Facilities Council (STFC) studentship.

Additional eligibility requirements

These pay UK/EU tuition fees and a maintenance allowance.

EU students who do not meet eligibility requirements still qualify for the UK/EU fees rate, but not the STFC maintenance allowance.

Observables from extreme mass ratio inspirals in the post-LIGO/Virgo era

Supervisor: Prof. Silvia Zane

The first detection of gravitational waves (GWs) by the LIGO and Virgo collaborations in 2015 and 2016 have heralded a new era in multi-messenger astrophysics. However, such detections are limited by technological constraints to higher-frequencies of gravitational waves, corresponding to smaller-mass compact binaries with reasonably small orbits. The ESA-NASA Laser Interferometer Space Antenna (LISA) observatory will be the successor to LIGO and Virgo, a space-based interferometric triangle of detectors capable of detecting hitherto inaccessible regions of the GW frequency domain, such as ultra-compact binaries, supermassive black-hole (SMBH) binaries, and extreme mass ratio inspirals (EMRIs).

The systems producing GWs and their electromagnetic (EM) counterparts are highly dynamical, and require solving Einstein’s field equations (EFEs) in the time-dependent and nonlinear regime. Proper modelling of such systems requires simultaneously solving the EFEs for the background spacetime (e.g., compact binaries comprising BH, neutron star, white dwarf) along with the general-relativistic magnetohydrodynamical (GRMHD) equations of the accretion flow, and is highly non-trivial.

This project will begin by using GRMHD simulations of a single BH, modelling the effects of tidal disruption events (TDEs) on the observed emission properties, extracting meaningful observational signatures. With this foundation in place the next step will be to investigate the orbit of a low-mass object (e.g., a stellar-mass compact object) around a massive object (e.g., a SMBH) – due to their high mass ratio these binary systems are known as EMRIs. Such EMRI events offer the potential to place stringent constraints on the properties of the central SMBH.

This is a theoretical-numerical project, requiring a strong numerical & computational background, as well as necessitating physical/phenomenological modelling and interpretation of synthetic observables.

Desired Knowledge and Skills

Undergraduate in physics/astrophysics

Strong computational and mathematical skills

Multi-messenger astrophysics of gravitational wave sources

Supervisor: Prof. Kinwah Wu

The direct LIGO/VIRGO detection of gravitational waves (GW) emitted by compact astrophysical objects not only confirmed a key prediction of general relativity but also opens up new opportunities for the investigation of physics and astrophysical in the extreme environments associated with the GW sources. The discovery of the electromagnetic counterpart of GW170817, which was due to a neutron-stars merger firmly established the viability and the importance of time-domain multi-messenger astronomy. GW sources are inhomogeneous classes of objects, and the frequencies/wavelengths of the GW are determined by the linear size of the emitter. As such, the associated physics processes that give rise to the multi-messenger signals would vary substantially among the systems which break the degeneracy of scaling in general relativity models. For instance, how does a neutron star interact with another neutron star before they undergo merging and how would the resulting black hole interact with the neutron-rich remnant debris after the merging process? What is the physical condition of the neutron-rich matter when two neutron stars are being fused into forming a black hole?  How does the electromagnetic radiation that the process generated is modified when a neutron star is in an in-spiral process into a massive black hole? How would the orbital dynamic of the neutron star be affected by the strong gravitational interaction and the spin-spin and spin-curvature interactions? The student will select one or two related tissues among those mentioned. The objectives are to develop a theoretical framework to model the multi-messenger signatures and to make predictions that can be tested by current and future instruments. It is phenomenological and theoretical project, emphasis on the astrophysical aspects of gravitational wave research.

Desired Knowledge and Skills

Creative and critical thinking, strong undergraduate training in astrophysics and in mathematical methods. Comfortable with both analytical and numerical calculations.

Revealing the Milky disk formation history with the Gaia data

Supervisor: Prof. Daisuke Kawata

European Space Agency’s Gaia mission (launched in Dec. 2013), which MSSL is heavily involved in, has made the second data release in April 2018, which provide the position and velocity measurements for more than one billion of stars in the Milky Way. These big data provide the information of kinematics of stars in the large fraction of the Milky Way disk for the first time. We are currently applying a Bayesian neural network model to measure the age and metallicity for the stars observed with the Gaia and ground- based spectroscopic survey. The combined information of the age, metallicity and kinematics for stars in the different region of the Milky Way disk must tell us the formation history of the Milky Way disk. However, secular evolution mechanisms, such as radial migration due to the bar and spiral arms of the Milky Way, and kinematic heating by the bar, molecular clouds and satellite interactions, move the stars from their birth place, making the current stellar structure different from the initial structure when they were born. Hence, to decipher the Milky Way disk formation history from the observational data of the current Milky Way, this project will develop a Bayesian model of the Galactic disk formation, including the inside- out disk growth and radial migration of stars. Then, we will fit the Gaia data with the model with Markov Chain Monte Carlo sampling, to understand the formation history of the Milky Way disk and the significance of the radial migration.

Desired Knowledge and Skills
Undergraduate in astrophysics. Strong computational skills.

Comet Science with LSST

Supervisor: Prof. Geraint Jones

The 6.7m Large Synoptic Survey Telescope – LSST – is currently being built in Chile ( https://www.lsst.org/ ). When in full operation, its 3.2 billion pixel camera will take over 800 wide angle images each night. The entire visible sky will be imaged twice each week. Prof. Geraint Jones has an affiliate PI role on the project, with responsibilities for analysing the expected wealth of information on the dust and ion tails of comets imaged by the telescope. The analysis will use adaptations of two existing sets of code to provide valuable and ground-breaking data on comets’ dust and ion tails from the bounty of scientific data that LSST will provide. One program suite will be used for the analysis of ion tails, and the other for the detailed analysis of dust tails. The aims are as follows:
 

Ion tails: The speed of the solar wind – a continuous, fast flow of plasma from the Sun – controls the orientations of ion tails. Comets can therefore provide point measurements of wind speed, complementing in situ spacecraft data. LSST’s sensitivity will allow the detection of much fainter tails than possible without dedicated professional telescope time, & over great angular distances, including tails originating outside the camera’s field of view. When in full operation, LSST tail positions will be routinely & rapidly analysed for active comets, providing tens of thousands of measurements which will be extremely valuable for solar & heliospheric science as they allow 3D tracing of dynamic wind structures.
 

Dust tails: Cometary dust grain trajectories are primarily influenced by gravity & radiation pressure. Our existing comprehensive model will be applied to observed comets to interpret tail orientations. The results should yield valuable information on comet nucleus activity, dust fragmentation, & the mass/charge ratios of grains from Lorentz force effects. 
 

The PhD project will involve the adaptation of the ion tail analysis code in Python, and its application to existing and new comet images. The development of routines to extract comet images from the LSST data for analysis will also be needed. The dust tail model is already written in Python, but will need some adaptation. Prior to the arrival of LSST data, the comet analysis codes can be tested on the untapped wealth of existing and new comet images obtained by space-based observatories, professional and amateur observers to prepare for LSST operations, and to generate results that will be valuable in themselves. The LSST project has very ambitious plans for Solar System data release ( http://lsst-sssc.github.io/dataProds.html ). Once in full operation, the results of the LSST ion tail analysis will be made public as soon as possible for the wider scientific community to use. During the final year of the PhD project, LSST will be providing scientific data, and the student will analyse those images. The student will compare the results of their analysis of LSST and other observations to other sources, e.g. observations and models of the solar wind, will publish the results in journals, and publicize them at international conferences, in collaboration with colleagues at other institutions.

Desired Knowledge and Skills

Undergraduate degree in astronomy, astrophysics, physics, or another closely-related field.

Good computational skills.

Microchannel plate efficiencies for high-mass anions at Titan and beyond

Supervisor: Prof. Andrew Coates)

The discovery of high mass (up to 13,800 amu/q) negative ions in the Titan ionosphere was one of the remarkable new results from the Cassini mission (Coates et al., 2007, 2009, Waite et al., 2007, Coates et al., 2010a, Wellbrock et al., 2013, Desai et al., 2017). In addition, negative ions and charged ice grains were discovered at Enceladus (Coates et al., 2010b, Jones et al., 2009) and negative ions at Rhea (Desai et al., 2018). The measurements were made with the Cassini Plasma Spectrometer (CAPS) Electron Spectrometer (ELS), which was designed and calibrated to measure electrons in the Saturn magnetosphere. Detailed interpretation of the high mass negative ions and nanograin signatures require the determination of the microchannel plate (MCP) efficiency for high mass negative ions.

 

In this project, we will conduct an experimental study of the MCP efficiency for high mass negative ions. We will use existing and extended ion beam facilities at UCL-MSSL, using MCPs and potentially a spare ELS, and we will use international facilities (e.g. for lab-based tholins and charged dust) as required. We anticipate that the results will be important for the interpretation of data from Cassini and JUICE, and in other work such as lab-based protein studies. There will also be the opportunity to use the new values in scientific studies in the Saturn system particularly at Titan and Enceladus.

 

Coates, A.J., F.J. Crary, G.R. Lewis, D.T. Young, et al., Discovery of heavy negative ions in Titan’s ionosphere, Geophys. Res. Lett., 34, L22103, doi:10.1029/2007GL030978, 2007.

 

Coates, A.J., A. Wellbrock, G.R. Lewis, G.H. Jones, et al., Heavy negative ions in Titan's ionosphere: altitude and latitude dependence, Planet. Space Sci., 57, 1866-1871, doi:10.1016/j.pss.2009.05.009, 2009.

 

Coates, A.J., A. Wellbrock, G.R. Lewis, G.H.Jones, et al., Negative ions at Titan and Enceladus: recent results, Faraday Disc., 147(1), 293-305, DOI: 10.1039/C004700G2010, 2010a.

 

Coates, A.J., G.H. Jones, G.R. Lewis, A. Wellbrock, et al., Negative Ions in the Enceladus Plume, Icarus, 206, 618–622, doi:10.1016/j.icarus.2009.07.013, 2010b.

 

Desai, R.T., A.J. Coates, A. Wellbrock, V. Vuitton, et al., Carbon chain anions and the growth of complex organic molecules in Titan’s ionosphere, Ap. J. Lett., 844:L18 (6pp), doi:10.3847/2041-8213/aa7851, 2017.

 

Desai, R.T., S.A. Taylor, L.H. Regoli, A.J. Coates, et al., Cassini CAPS identification of pickup ion compositions at Rhea, GRL, 45, 1704-1712, doi: 10.1002/2017GL076588, 2018.

 

Jones, G.H., C. S. Arridge, A. J. Coates, G. R. Lewis, et al., Fine jet structure of electrically-charged grains in Enceladus’ plume, Geophys Res Letters, 36, L16204, doi:10.1029/2009GL038284, 2009

 

Waite, J. H., Jr., D. T. Young, T. E. Cravens, A. J. Coates, et al., The Process of Tholin Formation in Titan’s Upper Atmosphere, Science 316, 870, DOI: 10.1126/science.1139727, 2007.

 

Wellbrock, A., A.J. Coates, G.H. Jones, G.R. Lewis et al., Cassini CAPS-ELS observations of negative ions in Titan’s ionosphere: Trends of density with altitude, Geophys. Res. Lett., 40, 1-5, DOI: 10.1002/grl.50751, 2013.

 

Desired Knowledge and Skills

Undergraduate in physics or related subject

Skills in laboratory work

Solar Orbiter: Studies of the Solar Wind Charged Particle Populations

Supervisor: Prof. Christopher Owen

UCL/MSSL is the Principal Investigator (PI) Institute on an international consortium providing the Solar Wind Analyser suite (SWA) of instruments for the ESA Solar Orbiter mission.   Using 3 scientific sensors, SWA will sample electron, proton, alpha particle and heavy ion populations at various distances down to 0.28 AU from the Sun (i.e. around a quarter the distance from the Sun to the Earth) and at high solar latitudes.  In particular, UCL/MSSL has designed and built the Electron Analyser System (EAS) for the SWA suite.  SWA partners in France, Italy and the USA have provided the Heavy Ion Sensor (HIS) and Proton-Alpha Sensor (PAS) for the suite.

The mission is currently baselined for launch in Feb 2020, with a back-up in October 2020.  SWA data will be available within a few weeks of the launch, and thus analysis of this new data set can begin within the first year of a PhD program starting in September 2019.  In particular, we aim to use cruise-phase measurements from the 3 SWA sensors to undertake studies of the nature of the solar wind particle populations, their variability and their links to the Sun.  In the (hopefully short) period between the start of the PhD and launch we will undertake background/ preparatory studies using data from previous missions.

Solar orbiter and example of solar wind electron populations
Many potential projects fall within the scope of the mission science plan (interested students may wish to consult the draft ‘Science Activity Plan’ https://issues.cosmos.esa.int/solarorbiterwiki/display/SOSP/SAP-related+work generated by the PI’s and ESA) and so a potential tailoring to the specific background and interests of a research student are possible.  For example, it is known that the solar wind electron population in general consists of 3 components:  A 'core' population of the coldest electrons which is nearly isotropic - approximately the same flux of electrons of a given energy may be detected in any direction; A 'halo' population occurs at somewhat higher energies, and shows a slight shift in average velocity with respect to the core, and thus provides a 'heat flux' in the solar wind; Finally, a 'strahl' population is often seen as a more energetic beam of particles streaming along the magnetic field. Together these different electron populations contain information about the processes occurring at the source region on the Sun, the magnetic connections of the sampled plasma back to the Sun and on the plasma processes (e.g. turbulence, wave-particle interactions and magnetic reconnection) which may be occurring within the solar wind itself. Separating the effects of these processes is a complicated task requiring high-cadence, high resolution data of the type that will be available from SWA EAS.  As a further example of the kind of science envisioned here, a student might undertake studies of both the global drivers and local properties of interplanetary shocks.  Shocks and other wave fronts are driven through the solar wind by many forms of solar activity (for example, CME eruption, co-rotating interaction regions).  These shock fronts will be captured in unprecedented detail as they pass the spacecraft by the execution of a trigger mode on SWA and other in situ instruments.

The results of such projects are critical to the success of the overall ESA Solar Orbiter program, and the student will thus also be an integral part of the MSSL science and science-planning team. There will also be opportunity to collaborate with our partners in France, Italy and the USA, who have provided the HIS and PAS sensors for the SWA suite.  This project will place the student in a good position to collaborate more generally and to find future positions e.g. within the Solar Orbiter community internationally.

Desired Knowledge and Skills

Undergraduate degree in physics or closely related topic;

Strong computational skills;

Strong interest in data analysis.

Understanding how elemental abundance varies with time in the solar atmosphere

Supervisor: Prof. Lidia van Driel-Gesztelyi

      Elemental abundance patterns are tracers of physical processes throughout the universe, with the cosmic reference standard being the solar chemical composition. Understanding how the Sun’s chemical composition varies in time and space provides insight into how mass and energy flow through the Sun’s atmosphere into the solar wind, and in turn, through the atmospheres of solar-like stars into stellar winds. The Sun mainly consists of hydrogen and helium, with trace amounts of heavier elements. Although its atmosphere (corona) should have the same elemental abundances as the surface (photosphere), easily ionized elements are enhanced by a factor 2-4 in the corona compared to their photospheric abundances; behavior known as the first ionisation potential (FIP) effect. Recent spectroscopic observations of the Sun have shown that the spatial and temporal variability of coronal composition is intrinsically linked to the evolution of the solar magnetic field. How variations in the coronal composition relate to changes in the magnetic field provides clues to the origin of solar activity (flares, jets) and the solar wind. One of the primary goals of the upcoming Solar Orbiter mission (due to launch in 2020) will be to establish the origin of the solar wind using these plasma properties.

     The aim of this project is to exploit the more than 12 years of spectroscopic observations of the solar corona from the joint UK-NASA-JAXA (Japanese Aerospace Exploration Agency) Extreme-ultraviolet Imaging Spectrometer (EIS) instrument onboard the Hinode (“Sunrise” in Japanese) spacecraft. This unprecedented, yet underutilised, archive provides a unique opportunity to conduct the first statistically significant study of the physical processes which govern variation in composition and elemental abundance across a range of spatial and temporal scales. The project will involve learning spectroscopic analysis techniques, analysing “big data” from a large archive, proposing and obtaining new observations with Hinode/EIS in Japan and combining the spectral data with imaging and magnetic field data using state-of-the-art techniques. This will provide an opportunity to advance scientific understanding and techniques in preparation for the launch of Solar Orbiter, an ESA-led mission with strong involvement from UCL/MSSL and the Solar-C mission currently being proposed to JAXA. The project will also involve close collaboration with international experts from Japan and the USA.

Solar active region as seen by SDO and Hinode

Figure 1: A solar active region (left panel) as seen by the Solar Dynamics Observatory spacecraft, with the field-of-

view of the Hinode/EIS instrument shown in white. Right four panels show the different plasma parameters that

can be derived using Hinode/EIS observations; intensity, Doppler velocity, first ionisation potential (FIP) bias and

plasma density.

Desired Knowledge and Skills

Undergraduate in astrophysics

Computational skills

Explosive energy release in solar and space plasmas

Supervisors: Prof. Sarah Matthews and Dr. Jonathan Rae

Explosive energy release in magnetically confined plasmas is a universal process, from the natural plasmas that exist in the solar system to fusion reactors such as tokamaks.  From stellar atmospheres, including our own Sun, to comet tails and our own near-Earth space, these environments store magnetic energy over timescales ranging between minutes and days, which is then explosively released over far shorter timescales and converted into plasma kinetic energy. This local process has large-scale consequences for the reconfiguring the magnetic field and particle energisation.   Stored energy is quickly converted into the rapid transport of bundles of magnetic flux away from the site, a variety of particle acceleration processes and the generation of electromagnetic waves.  What process or processes cause this explosive energy release across each local plasma environment is still hotly debated. 

Auroral beads
We have recently discovered that there is a repeatable optical signature of the explosive energy release within Earth’s environment (termed a magnetospheric substorm; Kalmoni et al., Nature Communications, 2018).  With this result, we have been able to identify that unstable electromagnetic waves are inextricably linked to this energy release, solving a crucial part of a 60 year old science question of what causes this explosive energy release in the near-Earth magnetotail.  

Solar flares, while representing a rather different parameter regime to the Earth’s magnetosphere, nevertheless display qualitatively similar repeatable optical signatures. The goal of this PhD is to build on the work done by Kalmoni et al. (2018) to investigate whether unstable electromagnetic waves are also playing a role in generating the signatures observed during the explosive energy release of solar flares.

Using existing software and building upon this research framework, the student will apply the techniques developed for magnetospheric sub-storm analysis to multi-wavelength observations of solar flares, from ground and space-based platforms, with a view to determining the presence of waves and comparing their characteristics with those observed in magnetospheric sub-storms.

Desired Knowledge and Skills

Undergraduate degree in Physics, with a strong interest in solar or space plasma physics
Strong computational skills in a relevant programming language (IDL, Matlab, Python)