Scientists using the James Webb Space Telescope have discovered an “inside-out” galaxy that formed about 13 billion years ago. Similar to large cities, the center of the galaxy has the highest density of stars. However, as you move from the city center to the “outskirts” of the galaxy, its density decreases, giving the galaxy an inside-out shape.
Scientists have observed similar-shaped galaxies forming over the past 10 million years, but JWST’s unique ability to look back billions of years allows us to explore truly ancient galaxies. It is revealed that the galaxy has come back to life in much the same way.
“The question of how galaxies evolve over cosmic time is an important question in astrophysics,” said Dr. Sandro Tacera, of the Cavendish Laboratory at the University of Cambridge, and co-lead author of the study. said. “We’ve had a lot of great data about galaxies over the past 10 million years and in our corners of the universe, but now we can use the Web to go back billions of years and take observations from the first billion years. The history of the universe brings up all sorts of new questions. ”
A galaxy this old has never been seen before, an inside-out galaxy
Astronomers generally agree that galaxies studied with previous telescopes that formed during the past 10 million years were usually studied in one of two ways. Some galaxies collect or accumulate gas from surrounding clouds and use it as material and fuel for new star formation, while others merge with smaller galaxies and grow. According to the study’s authors, discovering galaxies that matured so quickly, just 700 million years after the Big Bang, could help answer long-standing questions about how galaxies formed throughout the history of the universe. It is said that there is a sex.
“We expect galaxies to start small as gas clouds collapse under their own gravity, forming very dense stellar nuclei and possibly black holes,” Tacchera explained. “As the galaxy grows and more star formation occurs, it’s like a spinning figure skater. When the skater pulls on his arm, it gains momentum and spins faster and faster.”
Galaxies work in a similar way. As time passes and gas accumulates from farther and farther away, the galaxy rotates faster and faster. This explains why galaxies often form spiral or disk shapes, Tatchera said.
James Webb Space Telescope Pier Goes Back in Time
The study, part of JADES (JWST Advanced Extragalactic Exploration), involved scanning the various light spectra coming from NGC 1549 using JWST’s advanced instruments. This data allowed the team to estimate the number and location of old and young stars, which they then translated into estimates of stellar masses and star formation rates.
Remarkably, the researchers found that despite having 1000 times more stars than NGC 1549, the density at the galaxy’s center is similar to the giant elliptical galaxies seen today. We also discovered an inside-out distribution of star-forming galaxies that is usually associated with many things. Younger galaxies. The researchers say their model predicted this type of star formation. But before JWST, it was impossible to confirm these models back 13 million years.
“One of the many reasons why Webb was such a game-changer for us as astronomers is that we can now observe things that were previously predicted through modeling,” said co-author and C. said William Baker, a doctoral student at Bendish University. “It’s like being able to check your homework.”
Due to the compact nature of this inside-out galaxy, the research team said each individual image collected by JWST was “forward modeled” to account for “instrumental effects” during the data collection process. I am. The modeling included prescriptions for dust absorption and gas ejection, and revealed a large number of old stars in the galaxy’s center and active star formation in the surrounding outer disk. Furthermore, a second “clump” of star formation was also visible further out.
Their modeling also found that the mass of stars on the outskirts of the galaxy appears to double every 10 million years. The researchers say this is “very rapid”, as the mass of our Milky Way galaxy is expected to double every 10 billion years.
Was the early universe dramatically different?
In the study’s conclusion, the authors point out that the initial analysis of NGC 1549 suggests that conditions in the early universe may have been dramatically different from today. Specifically, the dense galactic core and high star formation rate mean that the early Universe had plenty of gas needed for this inside-out galaxy to form new stars at such a fast rate. They hypothesize that there may be. But they also acknowledge that further observations of galaxies that formed in this ancient time frame are needed to provide definitive evidence of a dramatically different early universe.
“Of course, this is just one galaxy, so we need to know what other galaxies were doing at the time,” Tatchera says. “Are all galaxies like this? We are currently analyzing similar data from other galaxies.”
“By observing different galaxies across cosmic time, we may be able to reconstruct the growth cycle and demonstrate how galaxies grow to their final size today,” Tacchera added. .
The research, “The core of a star-forming disk as evidence of inside-out growth in the early Universe” natural astronomy.
Christopher Plain is a science fiction and fantasy novelist and head science writer at The Debrief. Follow and connect with him ×, Check out his books at plainfiction.com or email him directly at christopher@thedebrief.org.
