Nebulas and stars

Observational Cosmology research

Explore our work in observational cosmology | Image credit: NASA, ESA and H.-Y. Chu (Academia Sinica, Taipei)

Observational cosmology is the study of the origin, evolution, and current structure of the Universe, enabled by the data gathered from the most powerful modern telescopes and instruments. We use measurements of the large-scale distribution of galaxies, distortions in images of galaxies caused by gravitational lensing, and observations of supernova explosions to answer fundamental questions.

Large scale structure

Galaxies are not distributed uniformly in space, but cluster together tracing the large-scale structure of the Universe. This large-scale structure is itself shaped by the nature of the primordial perturbations, and the interplay of gravitational collapse and cosmic expansion through the history of the Universe.

We use large surveys operated from both ground-based and space-based observatories to map the positions of millions of galaxies. By analysing the clustering patterns in these datasets we uncover information about how the Universe has grown over billions of years, which we use to investigate questions such as the nature of dark energy. 

Galaxy survey projects we're involved in

Gravitational lensing

Light doesn’t simply travel through the Universe in straight lines: its path can be bent by the gravitational effects of clumps of matter along its path. This deflection of light is called gravitational lensing and it can lead to both striking images of individual rare distant galaxies that have been stretched and magnified (known as “strong lensing”) and to much more subtle effects on the alignments of groups of galaxies (“weak lensing”) which can only be studied through statistical techniques applied to very large datasets.

At the ICG we study both strong and weak gravitational lensing. Our research reveals information on the contents of the Universe and the distribution of the dark matter which primarily causes lensing, on the nature of the source and lens galaxies, and even on the behaviour of gravity itself.

Gravitational lensing projects we are involved in

Transients

Astrophysical transients are phenomena that appear suddenly in the night sky, brighten for days to months and then fade away and disappear again. This includes novae (eruptions on the surfaces of white dwarfs), supernovae (the explosions of stars), tidal disruption events (stars ripped apart by black holes), and the still mysterious gamma-ray bursts and fast radio bursts. At the ICG, we specialise in the study of supernovae and tidal disruption events.

Supernovae

 At the ICG, we focus on three areas of supernova studies: 

  • Progenitors: understanding which stars explode as different types of supernovae and thus advancing our understanding of the life cycles of stars;
  • Explosion physics: working out the details of how these explosions occur and the physics behind them; and
  • Cosmology: some types of supernovae (famously, Type Ia supernovae that were used to first discover the accelerated expansion of the Universe) can be used to measure distances to their host galaxies and thus probe cosmology

Tidal disruption events

At the ICG, we work on discovering tidal disruption events (TDEs) in spectroscopic galaxy surveys (DESI, 4MOST) and studying the properties of the host galaxies of these events. This is an exciting new field of study, with plenty of open questions to pick from.

Transients projects we're involved in

  • Dark Energy Survey (DES)
  • Dark Energy Spectroscopic Instrument (DESI)
  • 4-metre Multi-Object Spectroscopic Telescope (4MOST)
  • Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST)
  • Hubble Space Telescope surveys (BUFFALO, SIRAH)

Recent highlights

Research outputs

Research Staff in Observational Cosmology

David James Bacon Portrait

Professor David Bacon

Director of ICG

David.Bacon@port.ac.uk

Faculty of Technology

PhD Supervisor

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Theresa Baker Portrait

Professor Tessa Baker

Professor

tessa.baker@port.ac.uk

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Dr Becky Canning

Deputy Director - Space

Becky.Canning@port.ac.uk

Faculty of Technology

PhD Supervisor

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Thomas Edward Collett Portrait

Professor Thomas Collett

Professor of Astrophysics

thomas.collett@port.ac.uk

Faculty of Technology

PhD Supervisor

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Robert Glen Crittenden Portrait

Professor Robert Crittenden

Professor of Cosmology

Faculty Director of Postgraduate Research

Robert.Crittenden@port.ac.uk

Faculty of Technology

PhD Supervisor

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Enrique Gaztanaga Portrait

Professor Enrique Gaztanaga

Professor

Enrique.Gaztanaga@port.ac.uk

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Or Graur Portrait

Dr Or Graur

Associate Professor in Astrophysics

Or.Graur@port.ac.uk

Faculty of Technology

PhD Supervisor

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Kazuya Koyama Portrait

Professor Kazuya Koyama

Professor of Cosmology

Kazuya.Koyama@port.ac.uk

Faculty of Technology

PhD Supervisor

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Seshadri Nadathur Portrait

Dr Seshadri Nadathur

Senior Research Fellow

Seshadri.Nadathur@port.ac.uk

Faculty of Technology

PhD Supervisor

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Peter Clark Portrait

Peter Clark

Research Fellow

Peter.Clark2@port.ac.uk

Faculty of Technology

PhD Supervisor

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Dr Wolfgang Enzi

Research Fellow

wolfgang.enzi@port.ac.uk

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Dr Shahab Joudaki

Research Fellow

Shahab.Joudaki@port.ac.uk

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Lisa Grace Kelsey Portrait

Dr Lisa Kelsey

Research Fellow

Lisa.Kelsey@port.ac.uk

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Karina Alexandra Rojas Olate Portrait

Dr Karina Rojas Olate

Research Fellow

Karina.Rojas@port.ac.uk

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Daniela Saadeh Portrait

Dr Daniela Saadeh

Research Fellow

Daniela.Saadeh@port.ac.uk

Faculty of Technology

PhD Supervisor

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Discover our areas of expertise

Observational cosmology is one of the 4 areas of expertise within the Cosmology and Astrophysics research area – explore the others here.

Gravitational waves

We're detecting cosmic gravitational waves and developing gravitational-wave observations as an astronomical tool.

Illustration of 2 merging black holes and the gravitational waves that ripple outward
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Theoretical cosmology

We're exploring the inflation of the very early Universe, the impact of dark energy on its geometry and developing tests to monitor its expansion.

galaxy space
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Astrophysics

We're working to better understand the basic building blocks of our Universe, the origin of stars, the formation and evolution of galaxies, and stellar population models. Explore our astrophysics research

Spiral Galaxy
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Research groups

Institute of Cosmology and Gravitation

We're researching galaxies and stars, large-scale structures, gravitational waves and dark energy.

Applied Physics Research Group

We're exploring research in quantum information technologies, quantum optics and quantum foundations and applied advanced materials.

 

 

Interested in a PhD in Cosmology and Astrophysics?

Browse our postgraduate research degrees – including PhDs and MPhils – at our Cosmology and Astrophysics postgraduate research degrees page.