Euclid Consortium : First science results

The Euclid Consortium, in which the Department of Theoretical Physics (DPT) Physics Section is involved, is publishing the first scientific papers based on observations made by the Euclid telescope. A number of scientifically exciting targets have been observed and analysed by scientists from the Euclid Collaboration during a phase of early observations, giving a glimpse of the unprecedented power of this telescope, which is designed to provide the most accurate map of our Universe over time. Exciting scientific results concerning the discovery of new free-floating planets, the population of globular clusters around nearby galaxies, the discovery of new dwarf and low surface brightness galaxies, the distribution of dark matter and intracluster light in galaxy clusters, and lenticular galaxies magnified at high time lag are described in a series of 10 scientific publications. In addition to these promising initial scientific results, the Consortium is also publishing the mission's reference articles on the same day, confirming Euclid's exceptional performance.

The Euclid Consortium

In collaboration with the European Space Agency (ESA), the Euclid consortium has planned, built and is currently operating the Euclid space telescope mission. This mission aims to map the extragalactic sky over a period of six years, providing unique data that may offer new insights into dark energy and dark matter. Launched on 1 July 2023, the telescope successfully began its cosmological survey on 14 February 2024.

The Euclid Consortium comprises more than 2,600 members, including more than 1,000 researchers from over 300 laboratories in 15 European countries, including the University of Geneva, as well as Canada, Japan and the United States, covering various fields of astrophysics, cosmology, theoretical physics and particle physics. Today, the efforts of the Collaboration can be demonstrated by a first series of Euclid publications. It is a great pleasure to announce the release of the first papers describing the Euclid mission, its scientific instruments and its performance based on the observations made by Euclid. Five of these will serve as key references throughout the mission and beyond, while the other ten present research carried out with the ERO (Early Release Observations) data.

Early observations images, data and documents

A programme of early observations was carried out during Euclid's first months in space to give a first glimpse of the depth and diversity of the science that Euclid will provide. A total of 24 hours was allocated to specific targets chosen to produce stunning images that are also relevant to scientific research. Five of these images were published in November 2023. The other five are being published today, 23 May 2024, by ESA.

The Euclid Collaboration has now completed some of the initial scientific analyses that have been carried out with these ERO data, and is publishing the associated papers and data today. Seventeen targets, ranging from galaxy clusters, nearby galaxies, globular clusters to star-forming regions, have been observed and analysed.

Scientific discoveries include: new candidate floating planets, newly identified extragalactic star clusters, new low-mass dwarf galaxies in a nearby galaxy cluster, and the discovery of very distant bright galaxies (observed in the first billion years of the Universe).

These scientific results demonstrate the excellent performance of Euclid and its ability to provide the expected precision for various targets, as well as the smooth and efficient analysis of the data within the Euclid Collaboration, which bodes well for the future of the mission. All these spectacular results were achieved in less than 0.1% of Euclid's allotted observing time.

Future Milestones for the Euclid mission

The next data release from the Euclid Consortium will be Euclid's primary science, with a first global fast release currently planned for March 2025 and a wider data release planned for June 2026. At least three further rapid releases and two further data releases are expected before 2031, which is a few months after the end of the initial Euclid survey.