Oxford Astrophysics will run a summer research programme for undergraduate physics students again in summer 2023. The selected students will work with a supervisor in the department, usually a postdoctoral researcher or lecturer, on a self-contained research project. The programme will also include lectures/seminars on current astrophysics topics, and on academic careers in astro. Students will be encouraged to take part in department life , joining researchers for coffee, discussions and seminars.
The projects run for typically 8 weeks, nominally from 3 July to 25 August. The duration may be adjusted slightly to be shorter or longer, or to accommodate summer travel. Students will be paid as employees of the University, receiving a payment of £11.35 per hour (subject to tax and National Insurance deductions). Students are normally expected to work full time on their project, but hours can be discussed with your supervisor. We will make sure that all computing resources needed for the selected projects are available to all selected candidates.
Application instructions, and the list of projects offered for 2023 can be found below.
Students currently in third year of a relevant undergraduate degree are eligible to apply. Students who have completed a 3-year undergraduate degree and are now taking a taught Masters course are also eligible, as long as they are not in their final year. Applications are welcome from institutes outside of Oxford. Unfortunately, due to UK visa regulations, we are only able to accept applications from candidates who do not require a visa to work in the UK. EU students currently in the UK who have been granted Pre-Settled status are also welcome to apply along with current students in the UK on a Tier 4 visa that allows vacation employment. If you have queries about your personal circumstances, please get in touch with firstname.lastname@example.org.
How to apply
To apply, submit a CV and a 1-page cover letter (in a single PDF file) while filling out the Oxford Astrophysics Summer Research Programme 2023 application form. The cover letter should summarise your academic accomplishments to date, your motivation for participating in the programme, and mention which of the projects advertised you might be interested in. You will also be asked to contact one academic referee who can provide a short letter in support of your application. Referees should submit their letter by filling out the Oxford Astrophysics Summer Research Programme 2023 referee form.
Deadline for applications: 24 March 2023
- The motion of matter in the local Universe: Bulk Flows and Optimal Estimators
Supervisor: Sebastian von Hausegger, Harry Desmond
Description: In our universe, galaxies and galaxy groups move due to their gravitational attraction. Dedicated astronomical surveys gather data on their positions, distances, and velocities, with which we can learn about this very motion in our Galaxy’s own environment. In this data-driven project, we will analyse galaxy catalogs in terms of their larger-scale dynamics, and cover a volume out to around 200 Mpc/h centered on our Solar System with the Cosmicflows-4 catalog. Specifically, we will revisit work on large-scale bulk flows and their proper statistical estimation. On the numerical side, the student will learn how to handle moderately sized astronomical data sets, and how to perform result-oriented computations. On the theoretical side, the student will become acquainted with basic cosmological theory and how to infer relevant quantities, e.g. by constructing and using maximum likelihood estimators.
- Characterizing quantum-limited superconducting amplifiers
Supervisor: Boon Kok Tan, Nikita Klimovich
Description: Description: The microwave frequency range is home to a wide range of astronomically interesting signals ranging from black holes, distant galaxies, and the cosmic microwave background. In order to measure the signals from such faint sources, the incident light must be amplified so that it can be adequately detected and digitized by the receiver electronics. At present, the noise introduced during the amplification step is often the limiting factor to the quality of data we can measure when observing the night sky. A new kind of superconducting technology, traveling wave parametric amplifiers, aims to solve this problem by amplifying signals while having quantum-mechanically limited noise performance. In this internship, we are looking for a student to help characterize the performance of new types of parametric amplifiers using state-of-the-art cryogenic instruments and measurement techniques. Once you are familiar with the requirements of these sensitive experiments, you will write code (python or other language) to interface with our cutting-edge microwave instruments to remotely control and automate these measurements for the future.
Recommended experience: Required Skills: some programming experience in a high-level language such as python.
- Why do quiescent galaxies not form stars?
Supervisor: Thomas Williams
Description: This project would measure the ability of molecular gas to form into stars via the Toomre Q instability parameter. Work ongoing by myself is applying this to a sample of late-type, star-forming galaxies, but quiescent, early-type galaxies remain poorly explored and an active area of interest. This is due to the fact that these galaxies are often rich in molecular gas but have little to no star formation ongoing, so something must be significantly different in the gas properties compared to star forming galaxies that halts this star formation. The Toomre Q parameter is often seen as the "holy grail" for predicting star formation, and so a systematic study of this quantity across a number of galaxies should shed important light on the lack of star formation in these galaxies. For this, the WISDOM galaxy sample is ideal. With our measurements, we probe the entirety of the molecular gas, that is confined to the inner kiloparsec of quiescent galaxies, at the resolution of 10s of parcsec. This is the typical size of a molecular cloud, the birthplace of all massive star formation and the natural fundamental unit of star formation. As such, we have a homogeneous dataset that can be used for robust comparisons between different galaxies, at a scale that is physically relevant, for the first time. We will use existing ALMA datasets, plus high-level products generated by members of the WISDOM team (e.g. mass models, rotation curves) to measure Q in a number of early-type galaxies and ask why quiescent galaxies do not form stars. Time allowing, we will also use VLT-MUSE measurements to link the star-formation efficiency to Q, diving deeper into how relevant the gravitational instability parameter is (or is not) for predicting locations of star formation.
- The cosmological tension in the amount of structure and the effect of baryons
Supervisors: Carlos Garcia-Garcia
Description: Current direct measurements of the parameter that quantifies the amount of structure in the Universe (S_8) are in 2-3sigma disagreement with the value predicted by the Standard Cosmological Model from Planck's Cosmic Microwave Background measurements. It has been shown that a reduction of the matter power spectrum at the non-linear scales level can reconcile both early- and late-Universe measurements. This kind of effect can be seen in some models of baryonic effects. In this project, we will use measurements of the large scale structure to produce a data-driven reconstruction of the non-linear scales matter power spectrum evolution and link it to current models of baryonic effects.
Recommended experience: python, cosmology/astrophysics.
- The functional form of the inflationary potential
Supervisors: Prof. Pedro Ferreira, Dr Deaglan Bartlett, Dr Harry Desmond
Description: Inflation – a period of accelerated expansion of the Universe right after the Big Bang – is a cornerstone of modern cosmology. However, the form of the potential that governs the dynamics of the inflaton field is completely unknown, with a plethora of theoretical proposals but no solid and general observational constraints. In this project the student will use the technique of symbolic regression, specifically the in-house “Exhaustive Symbolic Regression” algorithm [1,2], to discover plausible functional forms of the potential and of the power spectrum of primordial perturbations produced as a result of inflation. This involves generating all possible simple functional forms and calculating the number of e-folds of inflation, primordial power spectrum (specifically its spectral index), tensor-to-scalar ratio, the energy scale that they imply and the spectrum of fluctuations in the Cosmic Microwave Background in order to evaluate them against Planck data. The project continues work done by the Oxford Theory group , and has the potential to shed fundamental light on the initial conditions of our Universe.
Recommended experience: Ability to code in python (and willingness to learn machine learning techniques).
- Studying the properties of neutral hydrogen in optically identified galaxy mergers
Supervisor: Anastasia Ponomareva, Matt Jarvis
Description: Stars in galaxies form in dense giant clouds of molecular hydrogen, which in turn form from the cooling neutral hydrogen. Therefore, neutral hydrogen serves as a raw fuel to star formation. However, with the current consumption rates, it is unclear where galaxies keep obtaining gas to form stars. Some accretion events must be in play to sustain the average star formation rate in spiral galaxies. Mergers of galaxies is one of the possible mechanisms of such accretion scenario, where galaxies acquire minor companions to replenish they gas reservoirs. In this project the student will analyse the HI observations of the optically identified mergers of galaxies using the MIGHTEE survey, and study the signatures of mergers imprinted on the gas properties of merging galaxies.
- Modelling Disc Winds in Accreting Compact Binaries
Supervisor: James Matthews
Description: Description: Astrophysical systems made up of a compact object (a white dwarf, neutron star or black hole) accreting from a companion star are a rich laboratory for all sorts of extreme and exotic physics. Remarkably, as well as accreting material, compact objects often blast material into the surroundings in the form of “accretion disc winds”; fast, dense outflows which transport mass and angular momentum away from the system. Disc winds are detected through the presence of blue-shifted absorption lines in optical, UV and X-ray spectra, but they can also have other observational signatures that are less well-understood. In this project, we will use physically motivated models for disc winds to work backwards from the observations to infer disc wind kinematics, geometries and driving mechanisms. The precise direction of the project is flexible, but will involve building computational models for winds rising from the accretion disc and testing these against observations. The next step will be either to (i) conduct Monte Carlo radiative transfer simulations to predict the expected optical absorption and emission line signatures from disc winds in black hole binaries; or (ii) predict the radio emission from large-scale shock structures driven by winds in a range of accreting systems. The student will get to grips with some state-of-the-art techniques in computational astrophysics and get experience in analysing and visualising simulation outputs, while also learning about the cutting edge in observations of accreting black holes and white dwarfs.
Recommended experience: The student should be passionate about physics and astronomy, and be interested in programming, with some coding experience.
- A search for Hydroxyl as a signpost to galaxy mergers in the Universe
Supervisors: Matt Jarvis, Anastasia Ponomareva, Ian Heywood
Description: The star-formation rate and the assembly of massive elliptical galaxies are inextricably connected to how galaxies merge over cosmic time. Recently merged (luminous and ultra-luminous infrared) galaxies provide the perfect conditions for detecting Hydroxyl (OH) megamasers, which are often found within 1 kpc of heavily dust-obscured active galactic nuclei. OH megamasers are therefore ideal luminous radio beacons for tracing the merger history of the Universe. The Arecibo OH megamaser survey, which detected 52 masers out to z=0.23, represents the current state-of-the-art in our understanding of the nearby megamaser population. The MIGHTEE (PI Jarvis) survey will provide a unique opportunity to carry out a deep blind search for OH megamaser emission (and OH absorption) between z=0 and 0.85. The low redshift luminosity function of (15), would imply a detection yield a minimum of 10 OH megamasers. However, this number is highly dependent on the evolution of the galaxy merger rate as a function of redshift, which could easily lead to an order of magnitude more in MIGHTEE. In this project the student will use the new MIGHTEE data to search for OH megamasers and to place the first constraints on the merger rate of galaxies to high redshift using this information. A successful search of the data should lead to a publishable result.
- Using ram-pressure-stripped satellites to constrain baryonic feedback around galaxies
Supervisor: Adrianne Slyz, Julien Devriendt, Martin Rey
Description: Depending on their environment, galaxies exhibit large differences in their observed properties. For example, spirals in cluster cores are redder and have lower star formation rates (SFRs) than their isolated counterparts in the field. Observations of spiral galaxies falling toward cluster centres show tails of gas oriented away from cluster centres, suggesting that dense gas from the intra-cluster medium could be pushing the galactic gas reservoir in a strong wind, effectively quenching their star formation. However, both observations and theoretical predictions also seem to show that ram-pressure-stripping (RPS) can induce periods of enhanced SFR, as well as larger radial gas accretion rates, feeding the growth of a black hole and an active galactic nucleus (AGN). These RPS phenomena have also bee tied to the excess synchrotron radio emission that RPS galaxies show compared to isolated spirals, indicating that the magnetic field and cosmic ray electron densities are increased by the interaction of the swept gas with the galaxy. Therefore, understanding what processes affect RPS and give rise to this larger radio emission in these galaxies may give valuable information about the conditions of the gas around galaxies and how other physical components, like magnetic fields and cosmic rays (CRs), affect it. In this project, we propose the first study of RPS satellites in a cosmological high resolution simulation of a Milky Way-like galaxy including the effects of supernova feedback, magnetic fields and CRs. The aim of the project is to obtain mock synchrotron observations of selected satellites undergoing RPS to study the conditions required for enhanced radio emission, and how that relates to the magneto-thermodynamic state of the gas driven by CRs feedback.
Recommended experience: Knowledge of fundamental thermodynamics and fluid dynamics, with a basic-to-moderate knowledge of Python coding.
- Characterising the nuclear dust of the most obscured galaxy nuclei in the Universe
Supervisor: Ismael Garcia Bernete
Description: A significant fraction of the local luminous infrared galaxies population harbour an extremely compact and obscured nucleus with large hydrogen/dust column densities that make them undetectable in optical/X-ray wavelengths. Identifying these obscured sources is crucial to building an unbiased census of nuclear activity that enables us to better understand growth processes in galaxies. Submillimeter emission lines (e.g. HCN) have been used to identify them in the local Universe, however, expanding this method to more distant sources is challenging due to the faintness of this tracer. More recently, a new method has been proposed for selecting compact obscured nuclei based on infrared features (i.e. Polycyclic Aromatic Hydrocarbons). There is evidence that the embedded nuclear dusty structure of these sources can be explained by smooth dusty distributions. The goals of this project are two-fold: (1) to compute the predicted JWST near- to mid-infrared colors for these models as a function of their parameters. (2) to compare with real observations of luminous infrared galaxies using IDEOS database (Spitzer infrared measurements of galaxies). The results of this study will be key for future works using the unprecedented sensitivity+high spatial resolution of the James Webb Space Telescope.
Recommended experience: The project will involve some coding, mainly in Python.
- Gradient-based methods for parameter inference
Supervisor: Arrykrishna Mootoovaloo
Description: Parameter inference is central in any Bayesian analysis problem in Cosmology. In essence, given a set of data, we want to learn the parameters of a particular cosmological model. However, the latter is usually expensive, and one typically resorts to approximate inference method for learning the full posterior distribution of the parameters of the model. In general, MCMC methods are used but one needs a large number of samples to accurately map the full posterior. An alternative approach could be the use of gradient-based method such as Variational Inference (VI). A by-product of this methodology is an estimate of the log-marginal likelihood, which can also be used for model comparison. In this project, we will investigate the pros and cons of VI compared to MCMC method. For example, if we had a banana-shape posterior, will VI method accurately map the posterior? Is it a local process? Would VI be ideal in the regime where we have lots of data?
Recommended experience: Statistics, Cosmology, Python, Numerical techniques.
- Investigating interior compositions of rocky exoplanets and their atmospheres
Supervisor: Chloe Fisher, Tobias Meier
Description: Rocky exoplanets are expected to have interactions between their interiors and their atmospheres. This can lead to very different atmospheric compositions when compared with gas giants, whose atmospheres are dominated by hydrogen. By observing these terrestrial planets with ground- and space-based telescopes, we can obtain spectra of their atmospheres. Analysing these spectra and comparing them to physical models can allow us to detect different molecular species. In this project, we propose to use an open-source code to model exoplanets with different interiors and determine their atmospheric composition. We will use these outputs to produce atmospheric spectra of these planets, to determine what current or future instruments would be able to characterise them. The successful applicant will collaborate with experts in exoplanet interiors and atmospheres.
- A search for signatures of jet-ejecting galactic star systems
Supervisors: Katherine Blundell, Matt Jarvis
Description: This project will suit an intern with an aptitude for software development and mathematical/signal analysis. We wish to explore efficient methods for characterising light curves derived from different stellar fields in the sky from longitudinal photometric data streams. This is part of a programme to search for signatures of jet-ejecting galactic star systems, and will require the development of creative mathematical tools for efficient characterisation and filtering.
- Breakthrough Listen
We expect to host a number of summer projects hosted by the Breakthrough Listen collaboration. We will provide more details here as soon as possible.
Description: Breakthrough Listen is the world's most comprehensive, intensive, and sensitive search for extraterrestrial intelligence. We seek a scientific answer to one of humanity’s oldest questions: Are we alone in the Universe? With substantial amounts of time on some of the world's most powerful telescopes, our undergraduate researchers can get hands-on with development of search pipelines, instrumentation, machine learning algorithms, and citizen science projects to maximize the scientific return from our data. Students are involved in planning and executing remote observations at radio observatories around the globe, data mining and anomaly detection in archival data from space missions such as the Transiting Exoplanet Survey satellite, and pushing the frontiers of astrophysics in related areas including radio transients, high-resolution optical spectroscopy, and interferometry and beamforming. Prior astronomy research experience is not a prerequisite, but students with strong programming skills, Unix / Linux scripting, and / or machine learning experience have a track record of success working with us, including as lead authors on scientific publications resulting from their research.
- Exploring the Solar System parameter space for technosignatures
Supervisors: Chris Lintott, Steve Croft
Description: Over the ten year lifespan of the Vera Rubin Observatory’s LSST survey, we will catalogue ten times as many objects in the Solar System as are known today. The list will include more than 5 million asteroids, 100,000 near-Earth objects and more than 40,000 trans Neptune objects, many of which will be observed many times over during the course of the survey. This project considers the potential of this data set to search for technosignatures in the form potentially artificial objects within the Solar System. Using simulations of the LSST dataset where available, and a search of the literature, we will look for regions of the parameter space which are underoccupied by naturally occurring objects, with the aim of prioritising anything found with these properties for follow-up. The results will be of use for technosignature searches, but also for those hoping to find unusual and interesting members of the Solar System family.
- Radio AGN within the cosmic web
Supervisors: Matt Jarvis, Imogen Whittam
Description: We will use data from large spectroscopic surveys and radio continuum data to investigate whether the large-scale radio jet properties of accreting black holes (active galactic nuclei; AGN) in the centres of galaxies are related to their position and orientation within the filamentary structure of the cosmic web. The project will involve running code to determine the structure of the cosmic web from large galaxy redshift surveys and then to investigate whether the size and orientation of jets from AGN align or misalign with the filamentary structure, which would have implications for the ability of the AGN to either stimulate or truncate star formation along specific directions.