of james webb space telescope (JWST) has discovered a strange “inside-out” galaxy at the beginning of the universe.
This galaxy, named JADES-GS+53.18343−27.79097, existed just 700 million years after Earth’s birth. big bang It is about 1/100th the size of the Milky Way. But unlike most galaxies, its growth appears to occur from the inside out, with stars forming more rapidly outside its dense core than inside it.
Theoretical models predict that such inside-out galaxies should be common throughout the early universe, but scientists have until now lacked the ability to peer through the dust and gas that obscure galaxies from view. Ta. Now, thanks to JWST, researchers have confirmed that prediction with the oldest glimpse ever observed. They published their findings in the journal October 11th. natural astronomy.
“One of the many reasons why Webb was a game changer for us astronomers is that it allowed us to observe things that were previously predicted through modeling,” study co-authors said. william bakerA graduate student at the University of Cambridge wrote in a paper: statement. “It’s like being able to check your homework.”
Galaxies in our local universe grow in two main ways. One is to capture enough gas to form new stars, and the other is to merge with smaller galaxies. However, it remains unclear whether these are the only mechanisms or whether other mechanisms were present in the early stages of the universe.
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“The question of how galaxies evolve over cosmic time is an important question in astrophysics,” said co-first author. Sandro Taccherasaid the professor of astrophysics at the University of Cambridge in a statement. “We have a lot of great data about the past 10 million years and about galaxies in this corner of the universe, but now we can use the Web to go back billions of years and obtain observational data about the beginnings of the universe. A billion years of history brings up all kinds of new questions.
To investigate this question, the researchers looked at data on ancient galaxies collected during JWST’s JADES (JWST Advanced Extragalactic Exploration) survey. Light travels at a constant speed through the vacuum of space, so the deeper JWST probes into space, the more distant light will be blocked. further back It virtually allows astronomers to see.
After studying these observations in detail, astronomers have uncovered a new galaxy. By analyzing the light emitted by the star within it using JWST’s near-infrared spectrometer (NIRSpec) instrument, researchers were able to determine the star’s age.
They discovered that this galaxy has a very dense core, and its stars are surrounded by a rapidly forming disk of gas and dust. As a result, the size of the galaxy doubles once every 10 million years, compared to the Milky Way’s 10 billion years. Doubling rate per year. As these stars take shape, they slowly move toward the center, causing the galaxy to spin faster, like an ice skater pulling his arms closer to his body, the researchers said.
Now that they have found this galaxy, researchers say they will now look for galaxies like it.
“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 can reconstruct the growth cycle.” “We may be able to demonstrate how galaxies grow to their final size today.”
