CNN
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Galaxies that remain unchanged for 7 billion years – rare in the universe – observed by astronomers, giving you a glimpse into the history of the universe, adding a mysterious collection of relics or objects called “fossil galaxies.”
The strangeness of these spaces is that galaxies escape the expected evolutionary pathway after an early stage of intense star formation. Other galaxies expand and fuse with each other, but fossil galaxies remain virtually inactive. Like celestial time capsules, they provide snapshots into the ancient universe, allowing astronomers to examine the mechanisms of galaxy formation.
The newly discovered fossil galaxy (named Child J0842+0059) is about 3 billion light years from Earth, and is the most farthest and initially observed outside the local universe. It was discovered by a team of astronomers led by the National Institute of Astrophysics of Italy (INAF) using high-resolution imaging of a large binocular telescope in Arizona.
“INAF researcher and the first author of a study of the findings published in the Royal Astronomical Society’s Journal Monthle Notices on May 31,” said Crescenzo Tortora. “These objects are extremely rare because over time the probability of merging with another galaxy increases naturally.”
According to Chiara Spisiello, a researcher at the University of Oxford in the UK, astronomers believe that the largest galaxy will be formed in two stages.
“First, there’s the early bursts of star formation, very quick and violent activity,” she said. “We’re going to have something very compact and small, the ancestors of this relic.”
She added that the second phase is a prolonged process in which the proximate galaxies interact and fuse, begin dieting, causing very dramatic changes in shape, size and star populations. “We defined this relic as an object that almost completely missed this second phase, and formed at least 75% of the mass in the first phase,” Spisiello explained.
The obvious feature of fossil galaxies is that they are very old, compact and dense, and much more dense than our own galaxies.
“They contain huge (billions) stars like the sun, and they don’t form new stars. They essentially do nothing. They are records of very old cosmic fossils,” she said. “When the universe was really, really young, they formed. And for a few reasons we didn’t honestly understand, they didn’t interact. They didn’t merge with other systems.
Fossil galaxies are important because Michele Cappelari, a professor of astrophysics at Oxford University, is a direct link to large galaxy populations that existed billions of years ago. Those who were not involved in this study. As “living fossils,” they avoided the chaotic mergers and growth experienced by most other large galaxies. By studying them, we can reconstruct the conditions of the universe in the early stages and understand the first burst of star formation,” he said.
He added that it was a sudden and major problem that caused these galaxies to stop the formation of stars. “Evidence from both local and (far) observations suggests that feedback from ultra-large black holes could be caused,” Capelari said. “These black holes create powerful winds that expel or heat galaxy gases, preventing the formation of further stars. However, this remains an active field of research.”
Scientists initially identified children J0842+0059 in 2018 using a VLT survey telescope (VST) at a Delusion Observatory in Chile. The observation revealed that the galaxy is inhabited by very old stars, but only estimates of its mass and size were provided, so more detailed observations were needed to confirm that it was a relic. The large binocular telescope used for this confirmation can render very sharp images due to its ability to compensate for atmospheric turbulence.
The newly discovered fossil galaxies join only a handful of other groups observed at the same level of detail.
NGC 1277 and Kids J0842+0059 are very similar, but the latter is far from Earth. According to Spiniello, it fits almost perfectly with the definition of a fossil galaxy.
“This is what we call an extreme relic,” she said.
Fossil galaxies have stars and planets just like our own galaxies, but are much more dense, Spiniello added. “It’s going to be very crowded because there are more stars in the small, small volume,” she said. “And it’s much more difficult to find a solar system like ours. Many planets orbit around them because many planets can interfere nearby.”
Kids J0842+0059 looks at observers like it was 3 billion years ago. Because it takes time to reach Earth from the galaxy. Spiniello hypothesized that the artifacts are likely to remain intact forever, but scientists are unsure as they still don’t know why they are preventing interactions with other galaxies.
“There must be something that will prevent them from merging, but you can’t really predict what will happen in the future without knowing what,” Spidiero said.
According to Sebastian Comelen, a foreign astronomer at Instad de Astrophicica de Canaryus at the University of Laguna and the Spine, it is very difficult to confirm their nature as they are relatively rare and small compared to the relatively rare and small galaxies. Confirming the distant relic galaxy is a credit to the search strategy used to identify these objects and modern instruments, he said.
“The galaxy of artifacts is mystical,” Comerón, who was not involved in the study, added in an email. “The fact that some galaxies are now the pristine relics of the first large galaxies requires explanation.”
Astronomers can’t say how rare the rare artefact is, but Spiniello estimates that in every galaxy in the universe is “one in millions.” According to Spisiello, the Inspire project aims to find and catalog fossil galaxies, and discovered the discovery of Kids J0842+0059.
New instruments could make this search even more effective. Spisiello and Tortora are excited about Euclid, the European Space Agency’s telescope launched in 2023, with the aim of exploring dark matter and dark energy that also helps to observe fossil galaxies.
“Euclideans will be transformative,” Spiniello said. “Instead of observing one object at a time, that broad Sky Survey structure covers a lot more. The idea is to find every galaxy in a patch of the sky.
Checking the Relec Galaxy Kids J0842+0059 at such a distance is an amazing achievement, and the future in this field is extremely promising, Cappellari said in an email. “On ground with powerful new telescopes like James Webb and Euclid (which created the first image just a few months ago), and advanced adaptive optics, we can expect to find and study these artefacts further away.”
