PhD/MSc Project Details currently available

Please send all applications to Prof. Michael Smith in the first instance, or contact the project supervisors to seek more details about the programme.

Star Formation: Evolving Environments
(Prof. Michael Smith)

Near-infrared and optical observations with the VLT/VLTI, Gemini and future LBT, JWST and ELT objectives include the aim of resolving the immediate environment of young stars. These are the regions where material is accreted, jets are launched and collimated, and accretion discs evolve into protoplanetary discs. In collaboration with Bonn (Weigelt, Preibisch) and Heidelberg (Gredel, Herbst), a collection of high-mass young stars have been imaged in fine detail, and direct comparison with numerical simulations has proven very encouraging. Spitzer and ALMA predictions have already been published by Rosen (CAPS visitor) and Smith. This project is aimed at building on this programme by interfacing MHD simulations with a radiative transfer code to predict how jet precession, orientation and the magnetic field determine observed structures. A second project will study the effect of FU Orionis outbursts on protostellar cores via MHD simulations.

Martian surface science and impact cratering
(Prof. Mark Burchell)

How do materials typical of the Martian surface respond to high speed impact events? What traces of the shock history can we find in samples impacted at high speed in our laboratory? What does this imply for analysis in-situ on Mars at impact crater sites? This is a timely topic given the latest NASA Mars lander mission and planned future European Space Agency missions. Kent is not part of these missions, but we are leaders in impact studies and the questions above are very topical. The work would use our in-house impact facility and our materials characterisation facilities.

Impacts on Pluto
(Prof. Mark Burchell)

Pluto is a body which will be observed by a fly-by of NASA's New Horizon's spacecraft in 2015. This work will use laboratory impacts on ice targets to predict the effect impact cratering will have on Pluto's surface and what ejecta might be produced and where it might go. Kent is not part of the New Horizon's mission but we are experts on impacts on ices and this work will be very timely.

Comet structure and composition
(Prof. Mark Burchell)

As a result of extensive work on the data from the NASA Stardust mission to comet 81P/Wild 2, we have a chance to add significantly to our understanding of cometary science. As well as analysing real cometary dust using our in-house Raman spectrometer and scanning electron microscope, the student would use our light gas gun to produce analogue samples to those collected by the Stardust mission. As well as individual results we wish to generalise our work to a more complete picture of cometary bodies.

Impacts and complex organic molecules
(Prof. Mark Burchell)

The spread across the Solar System of complex organic molecules is an important precursor for life. Impacts play a role in this, both in terms of the distribution process, as well as in terms of adding complexity to the basic chemistry. We wish to investigate how impacts interact with increased complexity of organic molecules, building on our long term interests and activity in this field.

Structure and Physics of the youngest protostars
(Dr. Dirk Froebrich)

Stars are critical to the nature of the Universe. It is of great importance in astrophysics to understand the physical processes that govern the distribution and accumulation of stellar masses. The project will analyse the properties of protostars in nearby star forming regions drawn from our database and new upcoming surveys. Statistical comparisons of model predictions with protostellar observables (temperature, luminosity, mass, outflow luminosity) will lead to a quantitative proposition for which star formation model explains the currently available observational data best. Together with radiative transfer modelling we will investigate in detail the structure and physics of the youngest protostars and relate it to the environment they are in. This will lead to a better understanding of the time evolution of individual sources and the advance of star formation on scales of molecular clouds.

Molecular Hydrogen outflows from young stars
(Dr. Dirk Froebrich)

The formation of low and high mass stars is governed by accretion processes. However, these objects do not only accrete mass, they also eject large amounts of material in jets, outflows and winds. These outflows interact with the surrounding molecular material via shocks and transfer energy and momentum into the parental cloud. The brightness and length of the outflows give indications of the evolutionary stage of the driving young star, as well as about the conditions of the environment. This project will analyse near infrared narrow band molecular hydrogen emission line images taken with the UK Infrared Telescope. The survey covers about 150 square degrees along the Galactic Plane. It will determine how the statistics of molecular hydrogen outflows from young stars depends on the environment (high vs. low mass star formation; clustered vs. isolated star formation), as well as generating a complete, unbiased inventory of molecular hydrogen emission line objects over a large fraction of the Galaxy.

Star Clusters as Building blocks of our Galaxy
(Dr. Dirk Froebrich)

Star clusters are the building blocks of galaxies. The project will determine ages, metallicities, reddening and distances for our recently obtained large, homogeneous and luminosity limited sample of star clusters in the Galactic Plane. This will result in the largest known and well classified stellar cluster sample to date. Based on this sample (or selected sub-samples, such as a distance or age limited sample) the projected and spatial distribution of clusters in the Galaxy, depending on age and metallicities will be studied to learn about infant mortality and external cluster disruption processes (tidal stress, interactions with molecular clouds). The spatial distribution of stars within the clusters will be analysed by means of minimum spanning trees. Analysed with respect to the age of the cluster, we will have means to investigate the internal physical processes of cluster evolution (mass segregation, evaporation).

Direct Detections of the Asteroidal YORP Effect
(Dr. Stephen Lowry)

The YORP effect is a torque that can modify the rotation rates and spin-axis orientations of small asteroids in the solar system. YORP torques are caused by the combined effects of incident solar radiation pressure and the recoil effect from anisotropic emission of thermal photons. Several observed phenomena in asteroidal science indicate that such a torque acts upon the surfaces of asteroids and meteoroids, for which the YORP effect is the only realistic mechanism. Despite its importance, there existed only indirect evidence for the presence of YORP on solar system objects, until recently.

The first direct detection of the YORP effect was achieved by Dr Lowry and colleagues, by conducting optical and radar observational campaigns over 4 years on the small near-Earth asteroid, (54509) 2000 PH5 (Lowry et al., 2007, Science 316, 272-274; Taylor et al., 2007, Science 316, 274-277). Since then, the effect has been observed on just a few other asteroids due to the difficulties encountered in making such detections.

Dr Lowry is leads a new approved observational programme at the European Southern Observatory (ESO) that will make extensive use of the 8.2m VLT and the 3.5 NTT observing facilities over the next 4 years. This ESO Large Programme is designed to survey a large sample of small near-Earth asteroids at optical wavelengths to detect the YORP effect acting on these bodies, and to determine their likely surface compositions. Thermal-IR observations will be taken with the VISIR instrument, for detailed thermal analyses of their surfaces, important for constraining theoretical determinations of the strength of the YORP effect acting on our target NEAs.

This ESO programme is a collaboration with colleagues from the Open University, Queen's University Belfast, Max Planck Institute for Solar System Research (Germany), and NASA's Jet Propulsion Laboratory (California, USA).

The student will assume a major role in the overall analysis and scientific interpretation of the full optical and thermal-IR data sets (CCD imaging and spectroscopy) as well as participating in several observing trips to the ESO telescope facilities in Chile, and the United States.

Astronomical Observations of Cometary Nuclei at Optical and Thermal- Infrared Wavelengths
(Dr. Stephen Lowry)

The central icy cores of comets are remnant material from the original accretion disc of our solar system and preserve, to varying degrees, a record of the conditions that existed during its formation. Understanding the physical, compositional, and dynamical properties of comets is crucial if we are to understand how our solar system formed, its subsequent evolution, and how it will likely evolve in the future. This project will focus on Jupiter-family comets (JFCs), which are a subset of the known cometary population. Dynamical studies have placed their source region within the Kuiper Belt beyond Neptune, a vast reservoir of cometary bodies that formed in-situ some 4.5 billion years ago. Studying JFCs provide valuable insight into the physical and compositional properties of small Kuiper Belt Objects (KBOs), much too faint to be observed from Earth (see Lowry et al. 2008, In 'The Solar System Beyond Neptune' book, University of Arizona Space Science Series).

SEPPCoN is a large international collaborative project whose goal is to accumulate high quality physical data on cometary nuclei, and so far the collaboration has acquired a vast amount of data on a large sample of JFCs. The dataset includes thermal-infrared imaging data from NASA's Spitzer Space Telescope, as well as optical imaging from many large ground-based observatories. This PhD project will build upon the success of SEPPCoN, and the student will assume a major role in the acquisition of new data sets from international telescope facilities, mainly in Chile, to expand the sample. The student will also gain experience in processing and scientific analysis of large astronomical-imaging datasets.

Star Formation: Theory and Simulations of Clouds
(Dr. Jingqi Miao
and Prof. Michael Smith)

Gravity and turbulence compete to turn interstellar gas into stars. Other processes, however, such as feedback, magnetic fields and radiation influence the duel. Exactly how may be determined by an overwhelming amount of data from SCUBA-2, Herschel, SOFIA and ALMA through both imaging and spectroscopy. UKIDSS and VISTA provide NIR survey data. The implications will be aided by a set of model predictions which cover a range of physical possibilities. In these projects, we will execute an extended range of detailed simulations involving a wide variation in physical and dynamical processes to search for critical values of parameters. In two projects, SPH and finite difference codes will be further developed to include modules to interface directly with observable quantities.

High-mass Star Formation and the Structure of the Milky Way
(Dr. James Urquhart)

Massive stars (>8 M⊙ and 103 L⊙) have a profound impact on their environment. They shape the interstellar medium (ISM) with their strong stellar winds and ionizing radiation, regulating star (and planet) formation, and ultimately drive the chemical and physical evolution of their host galaxies. However, our understanding of the initial conditions required for their formation and the processes involved in the early evolution of massive stars are still rather poor. 

Our ability to make significant progress in this field has been dramatically enhanced in recent years with the completion of a large number of Galactic plane spectral-line and continuum surveys that cover the whole wavelength range from the near-infrared to the radio. This PhD project will exploit these multi-wavelength surveys to quantify the star formation across the inner Galactic disk and provide a truly global view of star formation throughout the Milky Way.

The primary aims of the project will be to use these Galaxy-wide surveys to: 1) determine the evolutionary sequence for massive star formation, the statistical lifetimes for each stage and the initial conditions; and 2) to use the Galactic distribution of these massive star forming clumps to construct a 3-dimensional map of the distribution of the dense gas across the Milky Way and evaluate the role the spiral arms and environment plays in the star formation process. 

If there are projects that you think are within our area of interest, that you are particularly interested in researching towards, please contact the appropriate member of staff directly, or if you wish to apply, please contact Prof. Michael Smith

Please note: at present, the offer of projects depends heavily on financial constraints.