Projects on offer for 2022 entry will be progressively added here in December. The projects themselves may evolve somewhat before October 2022.
Exoplanet Origins and Evolution - Dr James Owen
The last decade has seen an explosion of exoplanet detections. We now know most stars host a planetary system; however, these exoplanetary systems are incredibly diverse and unlike our Solar-System. Using the ALMA telescope, we have been able to image the planet-forming environments (protoplanetary discs) at unprecedented resolution and sensitivity. These images have revealed that these protoplanetary discs are being shaped and disrupted by planets forming within them. However, linking the properties of planet-forming discs to the observed exoplanet population remains an unsolved theoretical problem. This project involves building theoretical models of how forming planets will interact with their parent protoplanetary discs and linking them to current observations (see Picture). This project will allow the student to undertake sophisticated hydrodynamical computer simulations of planet formation, and/or become involved in state-of-the-art observations
Dusty Starforming Galaxies in Protoclusters - Dr David Clements
Exploring the Topology of the Epoch of Reionization with the 21cm Signal- Dr Jonathan Pritchard
One of the last frontiers of astrophysics is the first billion years of the Universe, when the formation of the first galaxies and black holes produced the first star light leading to a Cosmic Dawn. Observations of the 21 cm line of neutral hydrogen in the radio promises to open a window onto this period (z=6-27) for the first time. Interferometers like LOFAR, HERA, and SKA will map fluctuations in the 21cm signal, while single dipole experiments like EDGES and REACH hope to detect the all sky global signal. These new experiments are expected to provide new insights into astrophysics and cosmology and are already starting to provide interesting data. This project will explore measures of the topology of reionization with a view to better understanding how non-Gaussian information can distinguish different reionization scenarios. This work will also explore how topology can be used to help ensure the robustness of detections of the 21cm signal and its role in image analysis for SKA. Connecting these statistics to Bayesian analysis will help explore the possibility for constraining the astrophysics of galaxy formation at early times
Planet Formation in the Inner Disc-The First End to End Model- Dr Subhanjoy Mohanty
Super-Earth sized planets, orbiting very close to their parent stars, are a dominant outcome of the planet formation process. However, no concrete theory for their formation exists. To quantitatively understand how these planets emerge from the discs of gas and dust surrounding newborn stars, we have developed one of the most sophisticated numerical models to date of the gas structure in the inner disc. Building upon this, we propose to construct the first end-to-end model of planet formation in the inner disc.
We shall proceed in two steps:
(1) Incorporate dust dynamics and its feedback on the gas into our numerical model, to elucidate where and how, in the inner disc, dust grains amalgamate into planetesimals - 10-100 km sized rocky bodies that are the building blocks of planets.
(2) Carry out N-body simulations of the dynamical evolution of the planetesimals we form, including mutual collisions, pebble accretion and gas interactions, to study how the planetesimals grow into planets, and thus determine the architecture (planetary masses and orbital parameters) of the resulting planetary systems.
The work will require the student to have a strong grounding in theoretical physics and maths, and at least some experience in coding.
Stellar Brightness Variability and Exoplanets – Dr Yvonne Unruh
Exquisite stellar photometry, often driven by the search for exoplanets, has shown that stellar variability is ubiquitous: approximately half of all late-type stars in the Kepler sample show variability that is attributed to the presence of active regions that comprise starspots and faculae (faculae are smaller-scale counterparts of dark starspots and are typically bright). For planet-hosting stars, the brightness variations due to the active regions are one of the main nuisance parameters as they introduce noise and bias in the measurement and detection of exoplanet atmospheres.
The aim of this project is to model stellar brightness variations to connect stellar brightness variabilty to the contamination of exoplanet transit spectroscopy. A particular focus will be on the as-yet poorly understood facular contributions and their dependance on stellar effective temperature, activity level and metallicity. At the same time, the recent explosion of spectrally resolved transit data opens up the opportunity to directly map bright facular regions and thus test the numerical simulations that form the basis of the variability modelling.
The Earliest Stages of Planet Formation - Dr Richard Booth
We know that planet formation begins in protoplanetary discs – the cold discs of gas and solids found around young stars – but today little is known for certain about the physics that controls these discs. A key problem today is to understand the earliest stage in planet formation: how the solid particles that these discs inherit grow, evolve, and are eventually incorporated into planets. The arrival of ALMA, an array of telescopes able to probe the solids in exquisite detail, has shown that the leading model of their evolution must be wrong. Yet the reason why this model fails, and how to fix it, remains unresolved. In this project you will build a theory for how the solids evolve in protoplanetary discs and use them to explore what the latest observations from facilities like ALMA can tell us about how they evolve and how planet formation proceeds.
Molecules in the Atmosphere of Venus - Dr David L Clements and Dr Ingo Mueller-Wodarg
The discovery of phosphine in the atmopshere of Venus by observations with ALMA and the JCMT suggests that there is unexpected chemistry underway in the clouds, or perhaps even biochemistry. To further understand what is going on in the clouds Imperial College is leading a long term JCMT observing programme to study the variation of a number of molecular species, including phosphine, in the clouds of Venus. This PhD project consists of two parts. The first part is the reduction and analysis of the JCMT data from our long term observing programme. The second part will involve modelling the atmopshere of Venus and comparing models to the observational data. Dr DL Clements of the Astrophysics Group will lead the data reduction and analysis aspects while Dr Ingo Mueller-Wodarg of the Space Physics Group will lead the modelling aspects. This work will all be undertaken as part of the JCMT-Venus international legacy project.
- Exoplanets origins and evolution - Dr James Owen
- The most luminous galaxies in the local Universe - Dr Dave Clements
- Astropysics and cosmology from the 21cm line - Dr Jonathan Pritchard
- Cosmology with the next generation of CMB experiments - Prof Andrew Jaffe
- Planet formation and habitability - Dr Subu Mohanty
- The first quasars and supermassive Black Holes - Dr Daniel Mortlock
- Bayesian Analysis of the dynamic Universe - Dr Florent Leclercq and Prof Alan Heavens
- Bayesian analysis of weak gravitational lensing - Prof Alan Heavens and Prof Andrew Jaffe
- Searching for the most distant quasars - Dr Daniel Mortlock
- Higgs, Dark Matter and the Global Search for Physics beyond the Standard Model - Dr Pat Scott
- Direct Detection of Dark Matter and Global Fits - Prof Roberto Trotta
- Cosmology and Fundamental Physics with Euclid - Prof Roberto Trotta
- Extreme Dusty Star-Forming Galaxies - Dr Dave Clements
- The Nature and Evolution of 70 micron selected galaxies - Dr Dave Clements
- The X-ray-Starburst Connection in the Herschel Era - Dr Dave Clements
- Advanced statistical methods for astrophysical probes of dark energy - Prof Roberto Trotta
- The early Universe and cosmological parameters from the Cosmic Microwave Background, Gravitational Waves, and other observations - Professor Andrew Jaffe
- Determining the topology of the Universe from the Cosmic Microwave Background - Professor Andrew Jaffe
- Accretion Disks, Planet Formation and Habitability Around Red and Brown Dwarfs - Dr Subu Mohanty
- Towards optimal statistics of reionization a5 Emulating radiation from variable stars - Dr Yvonne Unruh nd the 21 cm signal - Dr Jonathan Pritchard
- Cool pre-main sequence stars: their surfaces and circumstellar environments - Dr Yvonne Unruh
- Understanding solar brightness changes on climate-relevant time scales - Dr Yvonne Unruh
- Gravitational lensing, dark matter, and black holes - Professor Steve Warren
- Exoplan et origins and evolution - Dr James Owen
- The most luminous galaxies in the local Universe - Dr Dave Clements
- Pushing the limits of high-z LSS structure cosmology - Dr Boris Leistedt
- Emulating radiation from variable stars - Dr Yvonne Unruh
- Cosmology with likelihood-free inference - Prof Alan Heavens
- The highest redshift quasars - Professor Stephen Warren