Black hole hungers for an entire galaxy

Astronomers have discovered a supermassive black hole that is “starving” its host galaxy. Once again, Webb is showing what it can do. The discovery could revolutionize our understanding of the interaction between black holes and galaxies.

Webb reveals: Black hole is starving galaxy

An international team led by the University of Cambridge observed a massive galaxy nicknamed “Pablo's Galaxy” (GS-10578) that existed for about two billion years after the Big Bang. Despite its size, comparable to the Milky Way, this galaxy has largely remained silent about forming new stars.

“In the early Universe, most galaxies form many stars, so it is interesting to see such a massive galaxy at this time,” said co-author Professor Roberto Maiolino of the Kavli Institute of Cosmology, Cambridge. “If it had enough time to reach this enormous size, the process that stopped star formation must have happened relatively quickly.”

With Webb's sensitivity, the researchers were able to detect large amounts of gas being ejected at speeds of 1,000 kilometers per second – fast enough to escape the galaxy's gravity. This gas stream, powered by the central supermassive black hole, ejects more mass than the galaxy needs to form new stars. In other words, the galaxy is starving because of the black hole.

However, interestingly, despite the violent process, the galaxy retains its disk shape and the stars move in an orderly manner. This again challenges previous assumptions about the turbulent effects of the halt in star formation on the structure of galaxies.

“We knew that black holes have a massive impact on galaxies, and maybe it's common for them to stop star formation, but until Webb we couldn't confirm this directly,” Maiolino said. “It's another reason why Webb represents such a big step forward in our ability to study the early universe and its evolution.”
Pablo's galaxy was starved by the black hole.
The work, published in Nature, is a significant step in understanding how supermassive black holes can influence the evolution of galaxies, providing direct evidence of their role in stopping star formation. Future observations will provide further insight into the coldest gas components and potentially reveal more about the complex relationship between black holes and their host galaxies.

See also: