New satellite data reveals how mysterious forces shaped universe

By Elizabeth Hunter

New satellite data has shed light on how mysterious gravitational forces may have shaped the universe.

The first survey data from the European Space Agency's pioneering Euclid satellite was made public today (March 19) and has led to a flurry of scientific advances that have furthered humanity's understanding of space.

Launched in July 2023, the satellite is mapping the universe with unprecedented accuracy - by examining more than one billion galaxies over a six-year period.

A team based at the Universities of Oxford, Portsmouth and Newcastle combined the power of citizen scientists and machine learning algorithms to sift through the more than one million galaxies seen in Euclid’s latest data, searching for strong gravitational lenses.

These phenomena occur when massive objects, such as galaxies, distort space-time so much that they warp the light from objects behind them into rings or arcs.

Such lenses are incredibly rare – researchers liken it to searching for needles in a haystack - but the team has identified 500 strong lens candidates.

Rarer still are systems that contain two galaxies being lensed by the same object. Four of these have been spotted and will help astronomers understand the shape and structure of the Universe.

University of Portsmouth PhD student Natalie Lines said “These lenses are already allowing us to learn about our Universe, but this is just the beginning for Euclid.

"The full Euclid survey will be a revolution for strong lensing”.

Despite covering less than 0.5 percent of the complete study area, the data is already proving to be a treasure trove for UK scientists.

Researchers from the University of Edinburgh are leading the UK’s involvement in data analysis and hosting the UK’s Science Data Centre for Euclid.

As a key part of the Euclid Consortium, Edinburgh processes huge amounts of data from the satellite before it is studied by teams in the UK and across the wider Euclid Consortium.

Astronomers at Lancaster University have used Euclid data to enhance their study of transients, objects whose brightness changes over a relatively short time.

Euclid’s immense power has helped researchers observe supernovae, the sudden bright explosions that occur when some stars die, long after they have disappeared from the view of observatories on Earth.

Dr. Chris Duffy, lead author of the research with Professor Isobel Hook from Lancaster University, said: “It is amazing to use Euclid to be able to see transients and their host galaxies in such spectacular detail, especially well before and after we would otherwise be able to see them from observatories searching for supernova here on Earth.

"This will allow us to increase our understanding of supernova and where they came from.”

The Euclid-AGN team of researchers found a number of supermassive black holes gradually accumulating gas in the centers of galaxies, published in work led by PhD student Teresa Matamoro-Zatarain at the University of Bristol.

Also known as Active Galactic Nuclei (AGN), they make up less than 10 percent of the galaxy population in the Universe.

Experts say that combining Euclid data with other multi-wavelength surveys is enabling a new era of AGN exploration.

"The combination of sensitivity and spatial resolution of Euclid truly creates a new era of big-data exploration," said Dr. Sotiria Fotopoulou, co-lead of the AGN Working Group in the Euclid Consortium.

In addition to leading some of the first scientific papers to come from this data, the UK has played a key role in the development of Euclid since its inception.

University College London’s Mullard Space Science Laboratory (MSSL) led the production of Euclid’s visible instrument (VIS), a powerful camera used to capture visible light from distant galaxies.

Elsewhere, a partnership of seven UK universities contributed strongly to the Science Ground Segment, which receives the initial data from the Euclid satellite and transforms it into data that scientists can work with instantly.

Professor Andy Taylor of the University of Edinburgh, who leads the UK Science Ground Segment and the gravitational lensing data analysis for the mission, said: “These latest results show just how powerful Euclid is for astronomy and how fantastically its data analysis pipeline is working, with such high-quality data over huge areas of the sky.

"The strong lensing results in particular, led by UK teams, are a huge advance of previous analysis. It has been a lot of hard work over many years to develop, but the results are amazing.”