Below you will find information on our PhD Studentships, and our MSc by Research programme.
The Astrophysics Group offers PhD studentships for research projects in astrophysics, leading to a PhD degree from the University of Bristol. The Group offers studentships funded by STFC or the University. While the number of such studentships is necessarily limited, the Group may also take well-qualified self-funded students. We also expect to offer at least one astrophysics PhD studentship as part of the UKRI Centre for Doctoral Training in Artificial Intelligence, Machine Learning & Advanced Computing. For all of these studentships, please follow the application process below.
We encourage applications from any suitably-qualified students (usually with a first class or upper second class degree in Physics or a related subject) from the UK or overseas. Applications received by 14th February 2020 will be given full consideration (later applications may be considered if places are available). The strongest applicants will be invited for a visit and interview day (usually in early or mid March). To apply, use our on-line application form, and for more information send us an email.
For information on funding, see this link. In particular, note that there is the possibility of University funding for exceptionally well-qualified overseas students. If you are interested in applying for University funding, please contact us as soon as possible to discuss your application.
There are additional studentships available for Chinese students, as described here. For these Chinese scholarships, the deadline is 20th January 2020, so please contact us as soon as possible if you are planning to apply.
PhD students carry out independent research under the direction of a member of academic staff in one of the group's areas of research interest, and the degree is awarded on the basis of examination of a thesis after three and a half years.
Examples of possible PhD research programmes are given below, along with the names of potential supervisors. Click on the headings for more details:
Using Machine Learning to Explore the Evolution of Active Galaxies with Euclid
Euclid is a European Space Agency (ESA) M-class mission, aiming to uncover the nature of the Dark Universe. This space telescope will map the majority of the extra-Galactic sky (15,000 sq. deg.) in the optical and near infrared bands with excellent spatial resolution. The combined data of Euclid and ground observations e.g. with the Large Synoptic Survey Telescope (LSST), will form possibly the largest astronomical dataset of the next decade with 10 billion detected sources.
This PhD project pertains to the preparation and exploitation of Euclid data. Specifically, the candidate will be part of the Photometric Redshift Organizational Unit (OU-PHZ) and the Galaxy and AGN Evolution Science Working Group (GAE-SWG). In anticipation of the Euclid launch (~2022), we will work with currently existing public large datasets (ESO VISTA Public Surveys, KiDS, DECaLs, PANSTARRS, etc). The focus points of this project include - but are not limited to - source classification with machine-learning methods, and AGN/galaxy coevolution studies.
Group member involved in this programme: Sotiria Fotopoulou.
Exoplanets: Atmospheric Characterisation with JWST
Exoplanets now number in their thousands, yet there is still only a fraction which offer the opportunity for more detailed study through observations. These strange new worlds are vastly different from our Solar System planets, but can potentially answer long-standing questions about the place our planet and solar system holds in the habitable universe.
A PhD position is being offered in observational astronomy using data from the Hubble and James Webb Space Telescopes to study the atmospheres of exoplanets. This project aims to answer the following questions: What are the atmospheres of exoplanets made of? How do they change with their environment, and can we find traces of their formation? How do clouds in their atmospheres change what we measure, and what are the clouds made of?
This position will involve observations, data analysis, modeling, and detailed interpretation.
Group member involved in this programme: Hannah Wakeford
Planets: Accretion, Erosion, and Giant Impacts
A PhD project is being offered in the area of planetary astrophysics on understanding the formation and evolution of the outer solar system. Several fundamental questions about the outer solar system remain unanswered, including: What was the initial size distribution of planetesimals, the building blocks of planets? What was the role of binaries during accretion into larger bodies? What processes led to the observed diversity of dwarf planets? What was the balance between collisional erosion and dynamical clearing in removing mass from the Kuiper Belt?
Group member involved in this programme: Zoe Leinhardt.
XXL: The Ultimate XMM Extragalactic Survey
We are major contributors to XXL, a 50 square-degree X-ray survey, and the largest XMM-Newton science project to date. This survey identifies clusters of galaxies from their X-ray emission and then characterises these systems using a wealth of multi-wavelength data. We use these systems to study the cosmic evolution of both the gaseous intra-cluster medium and of the galaxies that populate these systems. We are interested in how the clusters themselves grow over cosmic time, how the galaxies within them evolve both through time and with the dynamical state of the hosting clusters and how the properties of these systems can be used to constrain our understanding of the Universe as a whole. XXL is enabling the identification of new clusters over a huge range of distance from us, the most distant being seen in light emitted when the Universe was only a quarter its present age. Given this huge time-scale, the survey is ideal for studies of the time-evolution of galaxy clusters.
Possible PhD projects based on XXL include: the search for the most distant clusters; studying galaxy evolution in clusters; estimating masses of clusters from X-ray data to contrain cosmological models; studying the scaling properties of the clusters and their evolution; observing the Sunyaev-Zel'dovich effect of the clusters. This work will be carried out in collaboration with astronomers around the globe.
Observations of galaxies, from those at the highest redshifts to those in the nearby universe, inform our understanding of the multiple physical processes that drive galaxy evolution. By carrying out such multi-wavelength observations on galaxies near and far, using a full range of ground and space-based telescopes, we are exploring how star formation and stellar populations, environment, morphology and other properties are related in galaxies and how these relationships vary over cosmic time.
Group member involved in this programme: Malcolm Bremer.
The Sunyaev-Zel'dovich Effect
The scattering of the microwave background radiation by gas in clusters of galaxies is used to study cluster atmospheres and as a tool to measure the parameters that define the large-scale structure of the Universe. Observations are made using ground-based telescopes in the radio and sub-mm, and compared with X-ray data from satellite observatories. Theoretical aspects of the scattering process are also studied.
Group member involved in this programme: Mark Birkinshaw.
Similarity Breaking in Galaxy Clusters
Simple models predict that galaxy clusters should have fractal-like behaviour, with low mass clusters being identical to scaled down versions of high mass clusters. However, observations show that this is not the case. We are studying the scaling properties of clusters to learn about extreme physical processes related to cluster mergers, energy injection from active galaxies, and runaway cooling processes, that are believed to be responsible for breaking expected self-similar scaling.
Group member involved in this programme: Ben Maughan.
Galaxy clusters act as gravitational lenses, distorting and magnifying the images of background sources. Radio, sub-millimetre and infra-red observations are an efficient way to find new lenses, the study of which will enable us to estimate the mass of the lensing clusters. This provides en excellent way to examine the density structure and masses of these clusters, with a view to understanding the distribution of dark matter and the formation and growth of clusters of galaxies.
Group member involved in this programme: Mark Birkinshaw.
Weighing Clusters of Galaxies
Accreting Black Holes
At the centre of every galaxy is a super-massive black hole, and in a small fraction of galaxies, called Active Galactic Nuclei (AGN), a significant quantity of gas is flowing into the black hole. This accreting gas forms a disc which emits X-rays that we observe with space-based observatories such as Chandra, XMM-Newton and Suzaku. Detailed modelling of the X-ray spectrum from AGN can tell us about the black hole (e.g., is it spinning?) and the geometry of the X-ray source and disc. There is an opportunity for both theoretical and observational X-ray projects related to black hole accretion flows. In particular, I am interested in looking at the variability characteristics of AGN (e.g., time lags as a function of X-ray energy and Fourier frequency) and how this can be used to "echo map" the inner disc and infer the physics of the accretion flow.
Group member involved in this programme: Andrew Young.
The Astrophysics Group has a thriving programme for research masters degrees (MSc) for self-funded students. Masters students carry out an independent research project with support from a member of academic staff which is assessed on the basis of the examination of a thesis after one year of research and up to two years of writing up (part time study is also possible). Students are expected to attend advanced undergraduate and postgraduate lecture courses in relevant subjects, and follow courses of directed reading, but the emphasis of the programme is on research rather than the taught element.
Projects are available in all of our research areas, several possible/recent MSc projects are given below:
Near-Field Cosmology and Galaxy Evolution
Groups of galaxies provide laboratories for the effects of galaxy-galaxy interactions on galaxy evolution, because the relative velocities between the group members are similar to the internal velocities of stars in the galaxies. We have several potential projects to study the nature and evolution of group galaxies using both imaging and spectroscopic data.
Dwarf Galaxies in the HST Treasury Survey of the Coma Cluster
The HST Treasury Survey of the Coma Cluster has obtained deep, high resolution images of large areas of the Coma Cluster, the closest very massive galaxy cluster. We have several projects concerned, generally, with the dwarf galaxy content of the cluster and evolutionary processes which affect the dwarfs in this dense environment. In addition we have a specific project to explore what are called post-starburst galaxies and the populations of star clusters which may form in these bursts, thought often to be induced by close interactions and mergers.
Black Holes: Reflection spectra produced by flares above an accretion disks
This is a theoretical and numerical project to compute the time-dependent X-ray spectrum produced by X-ray flares above an accretion disk. The project requires integrating photon paths through the Kerr metric from point-source flares at arbitrary locations above the accretion disk to calculate the flux incident on the disk, and from the observer to the accretion disk to determine what will be observed. The purpose of this project is to produce a general purpose model that can be incorporated into computer programs used to fit X-ray observations of black hole accretion disks. The project is theoretical and numerical, and a knowledge of general relativity (e.g., the Kerr metric) is required.
Black Holes: Iron line emission from accretion disks with misaligned jets
The bipolar jets produced by accreting compact objects can generate intense X-ray radiation. These X-rays will illuminate the accretion disc, and produce an iron fluorescence line. Previous calculations of this phenomenon have assumed that the accretion disc rotation axis and jet axis are aligned. If these are misaligned, it is possible that the X-ray illumination of the disc is enhanced and hence the iron fluorescence line is also enhanced. The objective of this theoretical and computational / numerical project is to calculate the iron line produced by accretion discs illuminated by a misaligned jet.
Fractal Galaxy Clusters
Simple models predict that galaxy clusters should have fractal-like behaviour, with low mass clusters being identical to scaled down versions of high mass clusters. However, observations show that this is not the case, and give evidence for extreme physical processes at work in clusters (such as mergers, active galaxy energy input, and runaway cooling) that break this self-similar scaling. This project will be an observational study of low mass clusters, where the similarity breaking is found to be the strongest, in order to better understand the differences from fractal behaviour, and their causes.
The Evolution of Galaxy Clusters
Clusters of Galaxies are highly luminous X-ray sources, allowing them to be studied observationally out to high redshifts. Such studies have given conflicting results on the evolution of galaxy cluster properties, and there is debate in the literature as to whether clusters obey the simplest model for their evolution or if additional factors are present. In this project we will investigate the evolution of the X-ray properties of galaxy clusters using several large samples at different redshifts to properly include selection biases in our analysis. The project will consist of analysis of large amounts of observational data, and statistical treatment of the results, including sample selection biases.
Cluster Magnetoacoustic Waves
As galaxies move through the atmospheres in clusters of galaxies they must emit long-wavelength magnetoacoustic waves. These can propagate through the cluster atmosphere, and will dissipate to cause heating. The question of cluster heating is of considerable importance: without some heat source, perhaps this one, cluster atmospheres would undergo collapses within a Hubble time, generating hypermassive galaxies. This project will be theoretical (and likely computational), and should produce an interesting short paper within the year.
Who to contact:
If you are interested in any of our postgraduate opportunities, send us an email.