Astrophysics

The Astrophysics theme is active in several research areas, specialising in cosmology, the formation of clusters and galaxies, active galaxies, high-energy astrophysical processes and the formation of extrasolar planets. Observational work in the theme uses large ground-based and satellite telescopes from the radio to the X-ray bands, whilst our theoretical work is tied closely to the interpretation of these data. 

The current specific areas of research are:

• Active Galaxies

We’re studying active galactic nuclei, particularly radio galaxies, using radio, infra-red, optical and X-ray techniques and looking at the environments and dynamics of radio sources, unified models for both high-power and low-power objects, observation and modelling of jets and the X-ray/radio relationship in radio galaxies and quasars.

• Black Holes

We’re studying the environment immediately surrounding black holes using space-based X-ray observatories along with observations at other wavelengths. We’re also probing the properties of the black hole itself using X-ray spectroscopy of gas deep in the potential well of the black hole, where the effects of strong gravity are important.

• Clusters of Galaxies

We are attempting to measure the most accurate masses possible for a large number of galaxy clusters by combining observations of the hot gas in clusters made with X-ray observatories with measurements of the Sunyaev-Zel'dovich effect, measurements of the gravitational lensing effect of clusters and the velocities of the galaxies within clusters.

• Data-intensive Astronomy

We are contributing to the Euclid space mission by creating Machine-learning classification models, and study Active Galactic Nuclei using multiwavelength data. Our work has direct impact on understanding the evolution of galaxies with cosmic time.

• Exoplanet Atmospheres

We are using the Hubble Space Telescope to perform large-scale surveys of exoplanet atmospheres and will be using the James Webb Space Telescope in the coming years to look even deeper into exoplanet atmospheres. These studies will help shed light on our own solar system and will also feed into planet formation modelling.

• Galactic Line Emission

Our research on the photo-excited component of the interstellar medium continues through our involvement with the international southern H-alpha survey of the Galactic plane and some other important Galactic and extragalactic regions.

• Galaxies and their Evolution

We are studying galaxy populations and their evolution using surveys of nearby galaxies to look for previously undetected low surface brightness and compact galaxies, and observations of more distant clusters and groups to look for evidence of the evolution of their galaxy content.

• Next Generation Radio Astronomy

We use radio telescopes to investigate the formation and evolution of galaxies, giving us a view into processes not visible at other wavelengths. We are observing both the neutral hydrogen, as the raw material for star formation, and the radio continuum emission from star formation and active galactic nuclei, using state of the art radio interferometers, including the South African telescope MeerKAT, and in the future, the Square Kilometre Array.

• Planet Formation and Collisional Evolution

We are developing a state-of-the-art numerical method that will include the most realistic model of planetestimal evolution to date. Our goal is to develop a complete account of planet formation.

• Stellar Structure and Nucleosynthesis

We study the production of chemical elements in stars. We also study how mass transfer from a binary companion can influence the composition of a star, leaving observational signatures long after the companion has faded away.

• Virtual Observatory

We are developing software and standards to connect astronomers to data providers around the world as part of the International Virtual Observatory Alliance.