- Active supermassive black holes can inhibit star growth Even far outside their home galaxy. That’s according to a new study by researchers at the University of Arizona.
- When these active supermassive black holes spew out powerful radiation, We call them quasars. We’ve known for a long time that quasars can shape the evolution of their home galaxies. But new research shows they also affect distant galaxies.
- Researchers observed weak signatures of star formation In a galaxy near a quasar. This suggests that galaxies do not evolve in isolation, but as part of an interconnected galactic ecosystem.
The University of Arizona published this original article on February 18, 2026. Edited by EarthSky.
Supermassive black hole prevents star growth in other galaxies
astronomers think black hole It exists at the center of most, if not all, galaxies. and February 18, 2026, University of Arizona said The powerful radiation they emit can slow the growth of stars in their host galaxy as well as in millions of other galaxies. light years Away. University of Arizona Zhu Yongda He led the research and discovered weak signatures of star formation in nearby galaxies. Vermilion said:
Traditionally, people have thought that galaxies are so far apart that they evolve primarily on their own. But we now know that one galaxy’s highly active supermassive black hole can influence other galaxies over millions of light-years away, suggesting that galaxy evolution may be a rather collective effort.
Mr. Zhu proposed this idea. galactic ecosystem And compare it to the intertwined ecosystems on Earth. Zhu said:
Active supermassive black holes are like hungry predators that dominate ecosystems. Simply put, it swallows matter and affects the growth of stars in nearby galaxies.
researchers published their peer reviewed study at Astrophysics Journal Letter December 3, 2025.
supermassive black hole
Since they were first predicted in the early 1900s, the destructive and eerie properties of black holes have fascinated scientists and the general public alike. Black holes, considered the most extreme objects in the universe, contain enormous mass and gravity, and can capture nearby matter and even light if they get too close. A small subset containing: milky wayThe central black hole of is known as super huge. They are millions, even billions, times more massive than the Sun.
As the name suggests, black holes themselves are invisible. But when a supermassive black hole actively eats up the material around it, it appears as a very bright spot in telescope images, sometimes emitting hundreds of trillions of times more energy than the Sun. Astronomers call these cosmic monsters: quasar. This is the stage in a black hole’s life when gas and dust form a swirling disk, releasing enormous amounts of energy as it spirals inward. Quasars often outshine entire host galaxies.
solve the mystery
Early observations from james webb space telescope In the early universe, there appear to have been few galaxies surrounding giant quasars. The results were surprising. That’s because large galaxies are typically found in dense star clusters, rather than isolated ones. Zhu said:
we were perplexed. …Then we realized that galaxies might actually exist, but were difficult to detect because very recent star formation had been suppressed.
That realization led to bold new ideas. Could these extremely bright, supermassive black holes not only affect their own galaxies, but also inhibit star formation in neighboring galaxies?
To test this idea, the research team studied J0100+2802, one of the brightest quasars ever observed. This quasar is powered by a supermassive black hole about 12 billion times the mass of the Sun. The light from these quasars allows astronomers to see the universe when it was less than a billion years old.
O III: Measurement of ionized oxygen
The team of scientists used the Webb to measure the emission of a specific gas called O III, an ionized version of oxygen that tracks very recent star formation in galaxies. The low O III ratio implies that ideal star-forming conditions in large clouds of cold gas are broken down. The research team observed distinct differences between galaxies within a million light-year radius of the dominant quasar. The galaxy exhibits weak O III emission compared to ultraviolet light, consistent with suppressed and very recent star formation. Zhu said:
Black holes are known to “eat” many things. However, during active feeding processes and in the form of luminescent quasars, they also emit very strong radiation. The intense heat and radiation split the hydrogen molecules that make up the vast interstellar gas clouds, eliminating their potential to accumulate and transform into new stars.
Stars require very specific conditions to form, including large reservoirs of cold molecular hydrogen. This serves as the raw fuel for star formation. Scientists already knew that quasars, which often sit at the center of young, rapidly growing galaxies, can destroy this gas within their own host galaxies, halting local star formation. But what remained unclear was whether this devastating effect extended beyond the quasar’s home galaxy. By using the Webb to observe light from quasars that existed more than 13 billion years ago, the researchers found evidence that the growth of much larger stars was being suppressed. Zhu said:
This is the first evidence that this radiation is affecting the universe on an intergalactic scale. Quasars suppress not only stars within their host galaxy, but also stars in nearby galaxies within a radius of at least 1 million light years.
the power of the web
According to Zhu, this discovery was not possible with other telescopes.
This is because by the time light from distant objects like quasar J0100+2802 reaches Earth, the expansion of the universe has stretched its wavelengths into the infrared. Previous telescopes were unable to clearly detect these faint infrared signals, giving Webb a unique ability to observe phenomena in the early universe.
Our galaxy, the Milky Way, probably once had its own quasars. Although currently inactive, researchers are wondering how this quasar influenced the formation of our own galaxy and the formation of other galaxies in its local environment.
The researchers hope to test whether this phenomenon extends to multiple quasar regions. And they want to understand exactly how galaxies are affected by neighboring quasars. They also want to know if other less obvious factors are at play. Zhu said:
Understanding how galaxies interacted with each other in the early universe helps us better understand how our galaxy formed. We now realize that supermassive black holes may have played a much larger role in the evolution of galaxies than once thought…acting as cosmic predators and influencing the growth of stars in nearby galaxies during the early universe.
Conclusion: A new study shows that supermassive black holes at the centers of galaxies can also slow star growth in other galaxies millions of light-years away.
Source: Quasar radiative feedback can suppress galaxy growth on the intergalactic scale at z = 6.3