On Thursday, May 23, the European Space Agency (ESA) and collaborators released a series of five images created by the revolutionary space telescope Euclid. The Euclid consortium previously published five images from the space telescope on November 7, 2023.
Euclid has been labeled Europe’s “dark universe detective” because its wide field of view allows it to track billions of galaxies across 10 billion years of cosmic history, providing astronomers with tools that can reveal more about two mysterious elements of the cosmos: dark energy and dark matter.
Even before he began collecting scientific data to unravel the mysteries of dark energy and dark matter, collectively referred to as the “dark universe,” Euclid demonstrated his potential with these two incredible sets of images.
That’s why Space.com asked several scientists in different fields to explain which of Euclid’s images from the two publications is their favorite so far and why.
Relating to: Euclid ‘dark universe detective’ telescope has revealed new images of the cosmos and they are remarkable
But first dark universe 101
Dark energy is the name given to the force that accelerates the expansion of the universe and pushes galaxies away from each other faster and faster. Looking at galaxies that existed when the 13.8 billion-year-old universe was just 4 billion years old can reveal how this force has evolved over time and help determine its true nature.
Dark matter is a form that is almost invisible in the universe because it does not interact with light. This means that it cannot consist of the particles that make up “ordinary” matter. However, because they have a gravitational effect, dark matter halos have affected the development of the largest structures in the universe. Euclid’s field of view is wide enough to capture these structures in a single image; This means it could help reveal how dark matter affects galactic evolution.
Dark energy makes up about 67% of the universe’s energy and matter budget, while dark matter makes up about 27%. This means that the “dark universe” along with stars, planets, the moon, people, cats, and the rest of the other everyday “things” that we understand (maybe not cats, to be fair) make up about 95% of the contents of the universe. for only 5% of the universe. To put it mildly, this makes the “dark universe” a big problem.
Euclid takes a walk on the dark side
Luz Ángela García Peñaloza is a cosmologist at Universidad ECCI in Columbia who studies the mystery of dark energy and its impact on cosmic evolution. This means that he followed Euclid’s development with great interest.
“Euclidean is observing the universe in a whole new way and will create a massive galaxy census. Personally, I find it fascinating how beautiful these first photographs look and all the surprising information they will reveal.” García Peñaloza told Space.com. “When I saw the images I had to take a deep breath because of their beauty and high resolution.”
When asked to choose his favorite image from Euclid publications, García Peñaloza chose one of the Abell 2390 galaxy cluster (below).
“It’s just breathtaking,” he said. “Any image that provides information about the distribution of galaxies in the large-scale structure of the universe will provide a handful of information about the nature of the ‘dark side’ of the universe.”
Italian astrophysicist Andrea Botteon of the Istituto di Radioastronomia: IRA (INAF-IRA) also selected the Abell 2390 image as the favorite of Euclid’s new cluster.
“As an astrophysicist who studies galaxy clusters, I can say that my favorite in the new release is the Abell 2390 image,” Botteon said. “With previously released image of the Perseus Cluster [below]”It demonstrates Euclid’s ability to recover very low surface brightness emission from galaxies and, in particular, intracluster light!”
Amateur astronomer Giuseppe Donatiello discovered 11 galaxies in astronomical survey data; nine of these were named after him, securing his place in astronomy textbooks. He explained that each expert would choose a different picture from Euclid as their favorite, depending on their field of study. He certainly has his own top pick, and this one comes from Euclid’s November 2023 set of photos.
“As a fan of dwarf galaxies in the Local Group and Local Universe, I was impressed by the detail in NGC 6822,” Donatiello told Space.com. “I’ve seen images of this galaxy taken with the most powerful ground-based instruments, but Euclid’s detail and depth are much higher. Clusters, nebulae and [globular clusters] Rather than blurry details in the Euclidean image, it is easily recognizable. I was lost in that field of vision for hours!”
Donatiello also chose his favorite image from the latest Euclid publications.
“The most interesting of the new ones to me is NGC 6744 because of the fine detail in the spiral arms of the galaxy,” Donatiello continued. “I also do studies dealing with stellar flows [stars and gas pulled from their galaxies by tidal forces]and Euclidean images contain information about star streams that I cannot obtain in low-resolution images. I hope the first public data will be published [DR1] Data from Euclid is as useful as data from other in-depth studies.
“If that’s the case, I’ll have fun too!”
David Kipping is an assistant professor of astronomy at Columbia University and studies the existence of moons around planets outside the solar system. He also selected an image from the previous version as his favorite Euclidean image so far.
“These are amazing images that show a truly impressive field of view. The Horsehead Nebula has to be my favourite!” Kipping told Space.com. “Of course, these images are for public consumption rather than science, so I’m especially looking forward to seeing the first results of the science.”
This new set of images and the previous set are part of Euclid’s Early Release Observations and were collected before February 14, 2023, when the space telescope begins main science operations. So both sets of spectacular images represent only a small fraction of the observations the telescope will make over the next six years during its primary mission.
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Although these new images and the previous set show Euclid is meeting expectations, the space telescope still has a lot to offer, García Peñaloza said.
“This is just the beginning of what we will see during Euclid’s lifetime,” García Peñaloza said. “I am confident that Euclid will shed light on our understanding of many cosmic mysteries. The best is still to come from Euclid!”