[ad_1]
Just like a basketball scout who discovers a bright, tall youngster, astronomers using the James Webb Space Telescope reported recently that they have spotted a small and fascinating group of baby galaxies in the early morning hours. These galaxies, scientists say, can grow into one of the largest mass conglomerations in the universe, a group of thousands of galaxies and trillions of stars.
The seven galaxies identified date back to 13 billion years ago, just 650 million years after the Big Bang.
“This is probably the largest system in the universe,” said Takahiro Morishita, an astronomer at the California Institute of Technology’s Center for Infrared Processing and Analysis. They describe the proto-cluster as the most distant and earliest observed entity. Dr. Morishita is the lead author of a report on the discovery, which was published Monday in The Astrophysical Journal Letters.
The scientists’ report is the result of a larger effort known as the Grism Lens-Amplified Survey of Space, organized by Tommaso Treu, an astronomer at the University of California, Los Angeles, to harvest the initial science results from the Webb telescope.
The telescope was launched into orbit around the sun on Christmas Day in 2021. With an infrared detector and a 21-foot wide main mirror, it is ideal for probing the early years of the universe. As the universe expands, galaxies so far away in space and time are fleeing from Earth at such a speed that much of the visible light, and information about them, has been generated at invisible infrared wavelengths, like a siren’s receding tone.
In its first year, Webb has recovered the bounty of bright galaxies and massive black holes that formed just a few hundred million years after the Big Bang.
The most recent baby galaxies have been detected in many years by the Hubble Space Telescope as red points of light, visible at great distances only because they have been magnified by the gravity of the space-warping Pandora Cluster, an intervening group of galaxies in the constellation. Sculpture.
Spectroscopic measurements with the Webb telescope confirmed that the seven points are galaxies and that they are all far from Earth. They occupy a region 400,000 light-years across, or about one-fifth the distance from here to the Milky Way’s closest cousin, the great spiral galaxy Andromeda.
“So our efforts to track down a known potential proto-cluster have finally succeeded after almost 10 years!” Dr. Morishita wrote.
According to calculations based on models of the universe, gravity will eventually merge these galaxies into a large cluster containing at least trillions of stars. “We can see distant galaxies like small drops of water in different rivers, and we can see that eventually they will all be part of one big and strong river,” said Benedetta Vulcani from the National Institute of Astrophysics in Italy and a member of the research group .
The spectroscopic data also allowed Dr. Morishita and his colleagues determined that the stars that inhabit some of these embryonic galaxies are surprisingly rich in elements like oxygen and iron, which must have been forged in nuclear furnaces over generations. from the previous star. Others among the infant galaxies are more pure. In theory, the first stars in the universe would have been composed of pure hydrogen and helium, the first elements to emerge from the Big Bang.
Some of these galaxies are giving birth to stars at an incredible rate, more than 10 times faster than the Milky Way, which is 10 to 100 times larger. Others in the young group were barely producing stars for one year, “which is an interesting diversity in a group of galaxies in this early epoch,” Dr. Morishita said.
All this raises the suspicion among some cosmologists that the early universe produced stars, galaxies and black holes faster than standard theory predicts. In an email, Dr. Morishita says there is no “crisis” in cosmology yet.
“A simpler explanation,” he wrote, “is that previous understandings of star formation and dust production in the early universe, which are complex, incomplete phenomena.”
[ad_2]
Source link