UCL Astrophysics Group


First Light

About First Light

Project First Light was an ERC funded research activity (2015 - 2023) whose principal goal is to examine the role that early galaxies played in driving cosmic reionisation. Via deep imaging in blank fields and through gravitationally-lensing clusters, galaxies in the reionisation era are examined spectroscopically using a variety of large ground-based telescopes. Lower redshift analogues of galaxies in the reionisation era are also studied in detail to understand the physical processes by which Lyman continuum photons are produced and can escape into the intergalactic medium. This focused observational activity is supplemented by a theoretical component based on numerical simulations incorporating radiative transfer and the modeling of nebular emission lines as a probe of the nature of the ionising radiation field. The group is actively planning programmes to be undertaken with future facilities including the James Webb Space Telescope - you can read about our accepted proposals on the James Webb Space Telescope here.

Latest News

Nicolas Laporte Receives the inaugural “Innovation Prize” at the French Embassy in London (November 2023)

Congratulations to former “First Light” postdoctoral researcher Dr Nicolas Laporte, who received the Innovation Prize for French residents in the UK at the Ambassador’s residence in Kensington on November 16th 2023.

The Innovation Prize recognises both Nicolas’ unique research achievements in studies of early galaxies and his dedication to public outreach, particularly to disadvantaged children. The citation highlighted Nicolas’s dedication in founding the InfiniSciences Association in Auvergne which
encourages famous scientists to share their knowledge with the public and young people. In the UK, Nicolas also developed complex 3D printed tactile models enabling visually impaired children to discover astronomy.

Well done Nicolas. We’re proud of you!

Dr Nicolas Laporte received the Innovation Prize for French residents in the UK at the Ambassador’s residence in Kensington.

Professor Richard Ellis receives 2023 Gruber Prize in Cosmology (July 2023)

Richard Ellis was presented the 2023 Gruber Prize in Cosmology at the conference “Shedding New Light on the First Billion Years of the Universe” in Marseille, France on July 6th. The shortened citation reads “Over the past five decades Richard Ellis’s innovations have reimagined cosmology in fundamental ways. His observations have pushed the cosmic horizon—how far across the universe we can see—to a period close to the development of the first galaxies. Meanwhile the instruments he conceived, then shepherded through development and execution, have transformed myriad astronomical methodologies.”

At the ceremony the full citation was described by Professor Jean-Loup Puget (Institut d’Astrophysique Spatiale, Université de Paris Sud, co-recipient of the 2018 Gruber Prize in Cosmology) and the award itself was presented by Sarah Hrera (Executive Vice President of the Gruber Foundation).

Richard Ellis received the Gruber Prize from Peter and Patricia Gruber Foundation 2023

Conference in honour of Professor Richard Ellis (June 2023)

On June 5 and 6, we celebrated Richard’s remarkable career and achievements via a two day meeting [LINK] held at the Institute of Physics. Postponed for three years due to the pandemic, over 50 of Richard’s former students, postdocs and collaborators came to London from places as distant as Sydney and Tokyo to the meeting entitled “RSE@70+: Observing the Evolving Universe.”

Supported by the ERC First Light grant, the P&A Department and the Perren Fund, talks and panel discussions debated progress in observational cosmology, large scale structure, astronomical instrumentation as well as the first results from the James Webb Space Telescope.

We thank Minh Cao for all her help running the meeting so smoothly.

Conference Photo - Observing the Evolving Universe

Richard Ellis awarded the Royal Medal at the Royal Society (February 2023)

Richard, who has tracked ever more distant galaxies over his career in a quest to find the moment of “cosmic dawn”, when stars first lit up the Universe, was awarded Royal Medal A, the Royal Society’s highest honour for the physical sciences. Previous recipients of the award include the Nobel laureates Professor Abdus Salam and Professor Sir Roger Penrose, and at UCL,  Sir Harrie Massey.

Richard was awarded the medal for “motivating numerous advances in telescopes and instrumentation, and exploiting these facilities to revolutionise the understanding of cosmological evolution”. The Society noted that Richard  “had foreseen the importance of applying new technologies, motivating him to raise funds, design and then exploit innovative instruments that have greatly accelerated progress [in the field]”.

Richard presented the Royal Medal by Prince Edward, Duke of Kent, at a ceremony at the Royal Society in February 2023.

1. The announcement by the Royal Society - Royal Medal Winners 2022

2. The announcement by UCL - Astrophysicist Prof. Richard Ellis honoured by the Royal Society

Guido Roberts-Borsani awarded the Chancellor’s Award for Postdoctoral Research at the University of California, Los Angeles (November 2022)

Guido Roberts-Borsani awarded the Chancellor’s Award for Postdoctoral Research at the University of California, Los Angeles

Congratulations to Guido Roberts-Borsani for receiving the prestigious Chancellor’s award at UCLA in November 2022! Guido was a former UCL postgraduate and postdoctoral researcher in the First Light team and remains a continuing collaborator.

The citation for his award highlights "his contributions to our understanding of the birth and early growth of galaxies... and his clear leadership in the planning analysis of the first observations with the James Webb Space Telescope." Well done Guido!

Richard Ellis identifed as one of the world's most influential researchers (November 2021)

Richard Ellis

Each year, Clarivate produces a list of “Highly Cited Researchers” - an elite group most frequently cited by their peers over the last decade.   The group comprises those individuals whose multiple highly-cited papers rank in the top 1% by citations in the Web of Science

This year, In the field of astronomy, Clarivate identified 104 astronomers world-wide and 12 in the UK, including Richard Ellis.  



Cosmic dawn occurred 250 to 350 million years after Big Bang 

24 June 2021

Members of the First Light team claim to have the first convincing evidence for when the first stars and galaxies began to shine. Their analysis indicates that this important moment, known as the “cosmic dawn,” occurred between 250 to 350 million years after the Big Bang. The researchers also calculated that the first galaxies, seen at their birth, will likely be sufficiently luminous to be detected with NASA’s James Webb Telescope due for launch later this year.

Discovering when the cosmic dawn began has been the life’s work of Professor Richard Ellis who commented: “The Holy Grail in observational cosmology has been to look back far enough that one might see the very first generation of stars and galaxies emerging from darkness. We now have convincing evidence of when the universe was first bathed in starlight and  hope to soon make direct observations of this event with the James Webb Space Telescope.”

The scientific article, led by Dr Nicolas Laporte with co-authors Romain Meyer and Guido Roberts-Borsani (all former UCL team members)  and Richard Ellis is being published in the Monthly Notices of the Royal Astronomical Society.

Further details can be found here.

Powerful telescopes probe to great distances, corresponding to ‘look-back times’ of billions of years in the past. The First Light team has studied six galaxies observed when the universe was only 550 million years old, corresponding to only 4% of its present age. However, by measuring the ages of stars in these early galaxies, it is possible to probe even further back in time. The team estimates that such galaxies first ‘switched on’ when the Universe was only 250 to 350 million years old, and the birth of similar systems would be within reach of the James Webb Space Telescope due for launch later this year. 

Credit: Nicolas Laporte / University of Cambridge

James Webb Space Telescope success for First Light group (April 2021)

A photo of the James Webb Space Telescope

The First Light group has had great success in the first cycle of accepted proposals for observing time on the James Webb Space Telescope due for launch on December 18, 2021. 5 proposals were accepted where a group member is Principal Investigator, and an additional 4 proposals accepted with a group member as Co-Investigator. This amounts to a total of 235 hours of observing time.

A list of the accepted proposals can be found here.

In addition to the First Light group’s success described above, it is interesting to note that 16% of all 83 accepted JWST proposals in the ‘Galaxies’ category are led by a current or former postdoctoral researcher or student supervised by Professor Ellis. In 1996 Professor Ellis was the only European-based member of the NASA ‘HST and Beyond’ committee that recommended the construction of what became JWST.

Yuichi Harikane wins prestigious award for young scientists (December 2020)

Yuichi Harikane
Congratulations to Yuichi Harikane (Honorary Researcher with the First Light team), who has won an Inoue Research Encouragement Award for Young Scientists from the Inoue Foundation for Science. This prestigious award is given to researchers under the age of 37 who have obtained a doctoral degree in the field of science and engineering in the last three years.



Richard Ellis awarded the Michael Faraday Gold Medal and Prize by Institute of Physics (November 2020)

Richard Ellis is awarded the Faraday Gold Medal
The Institute of Physics have awarded Richard Ellis the Michael Faraday Gold Medal and Prize, in recognition of over 35 years of pioneering contributions in faint-object astronomy. In awarding this honour, the IoP noted Richard's relentless efforts to push to earlier epochs through faint-object spectroscopy and the use of gravitational lensing, which have inspired generations of young observers who follow in his path. 


Important contribution to understanding when the first galaxies appeared in the Universe 

In May 2018, our team made an important contribution towards astronomers' understanding of the timescales during which the first galaxies appeared in the Universe, by studying a galaxy formed 250 million years after the Big Bang. These results come from observations carried out with the ALMA observatory and the Very Large Telescope.

Significant breakthrough in understanding the early formation of stars 

In March 2017, our team made a significant breakthrough in understanding the early formation of stars in the galaxy when the universe  was about 4% old.  This important breakthrough was reported globally and was the result of our dedicated research into understanding our universe.


Our project has seen a number of papers published, which are available on UCL Open Access and via our website.

A popular summary of our progress was published in EU Research.

About the Team

The team is led by Professor Richard Ellis, and supported by both Research Associates and PhD students.

There are strong collaborative links with research groups at the Royal Observatory Edinburgh, Caltech, the University of Arizona, University of California, Santa Cruz and the University of Tokyo. Please see our First Light Team page for more information on the team.

First Light group photo, UCL, October 2018 (from L-R: Rebecca Martin, Romain Meyer, Koki Kakiichi, Guido Roberts-Borsani, Richard Ellis, Kiana Kade, Sarah Bosman, Nicolas Laporte)