Jaw-Dropping Discovery: JWST Unveils Record-Breaking ‘Dead’ Galaxy That Lived Fast and Died Young in the Early Universe

Astronomers using the James Webb Space Telescope (JWST) have made a groundbreaking discovery. They found the most distant massive “dead” galaxy ever observed, which means that galaxies might have stopped forming stars much earlier than we thought.

When we talk about a galaxy’s “death,” we refer to its star formation slowing down or completely stopping. These types of galaxies are called “quiescent” galaxies. They lack the bright, hot blue stars typical of a young galaxy and instead host older, cooler red stars. JWST images have given these early galaxies playful nicknames like “Little Red Dots” because of their appearance.

The newly discovered galaxy is named RUBIES-UDS-QG-z7. Its light took 13 billion years to reach us, showcasing this galaxy as it existed just 700 million years after the Big Bang, making it the first massive quiescent galaxy observed in the young universe.

Andrea Weibel, an astronomer from the University of Geneva, expressed excitement over this find. She noted that RUBIES-UDS-QG-z7 formed an incredible 15 billion solar masses in stars before it stopped star formation so early in cosmic history. “This means it challenges our understanding of how large galaxies evolve,” she added.

Traditionally, scientists believed that galaxies took more time to stop forming stars. The presence of RUBIES-UDS-QG-z7 suggests that rapid changes occurred in the early universe, leading to an early halt in star formation for some galaxies. Current models don’t account for many such galaxies, making this find intriguing and somewhat surprising.

Quiescent galaxies are usually seen near our Milky Way, where they have had plenty of time to form stars and grow. But as JWST looks deeper into space, it keeps finding these galaxies at earlier points in time. Several were found just 1.2 billion years after the Big Bang. RUBIES-UDS-QG-z7 pushes that timeline back by another 500 million years.

Weibel explained that the discovery implies these early galaxies might have formed stars quickly and efficiently. “This galaxy is compact, which suggests that a lot of gas and dust collapsed into a small area to create stars in bursts,” she said. However, what makes RUBIES-UDS-QG-z7 unique is that it stopped star formation extremely early compared to other galaxies at that time.

Interestingly, while many Little Red Dots show signs of activity from supermassive black holes, RUBIES-UDS-QG-z7 does not. Its light comes solely from stars, adding to its unexpected mass and calmness.

Estimations suggest that galaxies like RUBIES-UDS-QG-z7 make up about one in a million galaxies. However, because of the limited area observed thus far, this number could change. With more observations from JWST in the future, researchers hope to explore a more expansive region of the sky to find out how common galaxies like this really are.

To gain further insights into RUBIES-UDS-QG-z7, astronomers plan to combine JWST data with information from ALMA, the world’s largest radio telescope array in Chile. This collaboration is expected to reveal more about the gas and dust in the galaxy, which is closely linked to its star formation history.

For further reading on this research, check out the original article published in The Astrophysical Journal.



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