The first full-color science images from the Euclid Space Telescope show crystal-clear views of hundreds of thousands of galaxies, star clusters, and other amazing cosmic objects.
These images are just a sample of what researchers hope the space telescope, located 1.5 million kilometers from Earth, will provide during its planned six-year flagship mission. This European Space Agency (ESA) project aims to study the large-scale structure of the universe and help solve the mysteries of dark matter and dark energy. Carol Mandel, ESA’s director of science programs, said in a webcast on November 7 that the images were released after the calibration and troubleshooting portion of the mission was completed and the mission was ready for daily science observations. He said it would show. “Today is a symbolic day,” Mandel said.
Cosmologists know that the parts of the universe that are well-understood, such as stars and other visible matter, electromagnetic radiation and other familiar forms of energy, account for only about 5% of what actually exists. The rest is dark matter and dark energy. The former is a substance that is almost invisible except for gravity, and the latter is a mysterious force that causes the accelerated expansion of the universe. Dark matter and dark energy similarly subtly influence the shape and arrangement of galaxies and galaxy clusters, which collectively form the filaments, sheets, and voids of the vast “cosmic web.”
Euclid launched in July to study the details of this vast structure using a state-of-the-art 600-megapixel visible-light camera and wide-field near-infrared spectrometer and photometer. The first image focuses on what we can see: spiral galaxies, elliptical spirals of stars, and clusters of stars like dandelion fluff pulled together by gravity.
“This is the beginning of an adventure,” says astrophysicist Adam Reese of Johns Hopkins University. Although he was not involved in the Euclid project, he led the team that discovered the accelerated expansion rate of the universe and shared part of the 2011 Nobel Prize. For that work he received a doctorate in physics.
The extraordinary sharpness and breadth of these images is a testament to the Euclidean telescope’s ability to survey large swatches of the sky with incredible clarity. Many of them offer vast views of well-studied regions that other telescopes could only reproduce by stitching together many time-consuming observations. In contrast, Euclid allows him to take such large snapshots in less than an hour. The telescope’s first snapshot of the Perseus galaxy cluster includes more than 100,000 galaxies, including some of the faintest galaxies ever seen.
The Euclidean view of nearby spiral galaxy IC 342 highlights the telescope’s sharp line of sight. This galaxy is usually hidden behind the Milky Way’s central plane, which is clogged with dust and gas. However, Euclid’s near-infrared camera can detect some of the heat emanating from this neighboring galaxy that passes through this shielding material intact. Researchers use pseudocolor to convert these invisible wavelengths into visible images.
“We study the rotation of these galaxies to find out exactly how much dark matter there is in the universe,” Guadalupe Cañas Herrera, a space scientist at ESA, said in a Nov. 7 webcast. I’m guessing that.”
The goal of Euclid’s mission is to create the most extensive three-dimensional map of the universe we have ever known. To accomplish that, the telescope’s survey will span a third of the sky and extend out to a distance of 10 billion light years. Given that the universe is 13.8 billion years old and the speed of light is finite, Euclid would investigate the evolution of the cosmic web from a time close to when the first stars formed. “We can explore parts of the universe for which we have very little data up until this point,” says Tanveer Karim, a researcher in observational cosmology at the University of Toronto who was not involved in the mission. .
In one new image, the irregular galaxy NGC 6822 shimmers like a haze, and its star-forming regions appear as purple (false-colored) bulges. The purple hue emerges from a galaxy’s mixture of ionized gas, which appears blue, and dust, which appears red. Another image spotlights the Horsehead Nebula, a star-forming region in Orion’s “belt.” Jason Rose, an observational cosmologist at NASA’s Jet Propulsion Laboratory, said in a webcast that using Euclidean sharp precision, researchers hope to discover brown dwarfs hidden in nebulae. Ta. Brown dwarfs are luminescent objects that are too small to be stars but too large to be considered planets. Learning more about how they form could help scientists understand the vagaries of the birth of stars and planets alike.
The telescope’s high-precision observations will enable unprecedented measurements. weak gravitational lens– Subtle distortions of light from background galaxies and star clusters caused by the gravitational field of intervening massive objects. Researchers can exploit these weak distortions to map the distribution of dark matter. The telescope will also study something called baryon acoustic oscillations (BAO). These are ripples in the density of matter that froze from the fiery plasma that filled the universe during the first 300,000 years or so after the Big Bang, and are thought to have influenced where galaxies subsequently formed. Mapping the distribution of distant galaxies could help reveal the existence and patterns of these ripples. These two currently vague measurements could help cosmologists pinpoint the exact rate of expansion of the universe.
Henk Hoekstra, an observational cosmologist at Leiden University in the Netherlands, said Euclid’s use of the BAO and weak gravitational lenses for its most spectacular measurements was akin to looking at an object at the bottom of a swimming pool. , said at a press conference after the image. ‘ release. The water in the pool in this metaphor is invisible dark matter and dark energy that distorts visible objects. Although we may not be able to observe water directly, we can infer information about the depth and flow of water by studying the distortions in objects.
“If we measure the shapes of these galaxies and average them, we can see how thousands of these galaxies exhibit preferred orientations,” Hoekstra said.
The amazing depth of Euclidean’s field of view is evident in this photo of NGC 6397, the second closest globular cluster to Earth. Thousands of focused lights, most of them distant, unnamed galaxies, lurk in the background. “We have this vast horizon,” Reiko Nakajima, an astronomer at Germany’s Agelander Institute for Astronomy at the University of Bonn, said at her recent press conference.
There are two competing general explanations for the dark energy that is currently causing the universe to expand faster than ever before, said Johns Hopkins Professor Rees. One is that dark energy is a cosmological constant, an immutable property of space, which means that the universe will continue to expand infinitely, forever sweeping away distant celestial bodies beyond our local perspective. It means that it means.The other thing is that dark energy. it’s not cosmological constant. This means that it can change radically over time. This can lead to two extreme and very diverse results. One is the “Big Crunch,” where dark energy becomes a gravitational force and causes the universe to collapse, and the other is the “Big Rip,” where dark energy is strengthened and torn apart. It destroys matter and destroys space-time itself. Reese added that there is a third overarching explanation. “Our current theory of gravity could be completely wrong, in which case all predictive bets would be off.”
“I don’t know what the answer will be,” he says. “That’s why there’s so much excitement around these approaches.”
Euclid is not the only project that comprehensively explores these questions. China’s Xuantian Space Telescope, scheduled to launch next year, is designed to map distant galaxies across 40 percent of the sky at a resolution similar to that of the Hubble Space Telescope. State news agency Xinhua. The ground-based Dark Energy Spectroscopy Instrument (DESI) at Kitt Peak National Observatory in Arizona is also searching for BAOs in the sky. And NASA’s Nancy Grace Roman Space Telescope, scheduled to launch in 2027, will also bring Hubble-like resolution to its own far-reaching exploration of the structure of the universe. towards the center of the Milky Way Signs of weak gravitational lensing, etc.
“We’re actually entering an era where we’re looking at the same part of the sky with multiple telescopes,” says Karim of the University of Toronto. “We can take advantage of different studies, complementing each other’s weaknesses. We can build a more comprehensive picture.”