Astronomers recently uncovered a remarkable story about a galaxy called Pablo’s Galaxy, or GS-10578. Using advanced tools like the James Webb Space Telescope (JWST) and the Atacama Large Millimeter/submillimeter Array (ALMA), they discovered that this young galaxy faced a gradual decline in star formation due to its central supermassive black hole. It’s like a long, slow fading instead of a sudden collapse.
Pablo’s Galaxy is quite distant—its light reached us after 11 billion years. That means we’re seeing it as it was just 3 billion years after the Big Bang. It’s massive, too, with enough mass to match around 200 billion suns.
Most of its stars formed between 12.5 and 11.5 billion years ago, but surprisingly, star formation seemed to grind to a halt due to the loss of cold gas, which is essential for new stars. This cessation signifies what astronomers see as a galaxy’s “death,” emphasizing how quickly it used up its resources.
In September 2024, researchers first revealed insights about Pablo’s Galaxy, focusing on how the black hole expelled massive amounts of gas at incredible speeds—about 2.2 million miles per hour. This process effectively prevented gas from forming new stars in the galaxy.
The ALMA observations looked for carbon monoxide, which can indicate the presence of cold hydrogen gas, but the results came up empty. Jan Scholtz from Cambridge University pointed out that even this absence of gas provided valuable insights into how the galaxy was slowly starved over time, rather than suffering a quick, catastrophic event.
Further investigations using the JWST showed that Pablo’s Galaxy loses approximately the mass of 60 suns each year in gas. This gradual loss suggests that it could run out of star-forming material in just 16 to 220 million years, which, while seemingly long, is quite fast compared to other galaxies.
Francesco D’Eugenio from the Kavli Institute looked into the galaxy’s formation history. He stated that the black hole’s influence kept new gas from returning to the galaxy, preventing it from refueling the star formation process. Rather than a single event causing its decline, multiple cycles of gas expulsion contributed to its starvation.
The findings from this research could explain why the JWST has been spotting many ancient-looking galaxies in the early universe. As Scholtz noted, it’s not always a dramatic event that halts star formation; sometimes, simply preventing new fuel from entering is enough. This might be why we see so many galaxies that “lived fast and died young.”
These studies open up exciting avenues for understanding how galactic evolution works. As researchers plan further observations of Pablo’s Galaxy, there’s hope for deeper insights into the complex relationship between black holes and star formation.
The research was published in Nature Astronomy on November 25. You can read more details about this study at Space.com and Cambridge University.
