Powerful Jets Hurl Gas Out of Distant Galaxy at Near Light Speed

Astronomers may have found out a little bit more about galaxy formation. They've discovered a powerful jet of material being propelled to near light speed by a galaxy's central black hole. This jet of material is blowing massive amounts of gas out of the galaxy, which is limiting the growth of the black hole and the rate of star formation.

Before now, astronomers have wondered why many galaxies aren't more massive than they are. They proposed two major mechanisms that could slow or halt the process of star formation and mass growth. There could be violent stellar winds from bursts of star formation and there could be pushback from the jets powered by the galaxy's central, supermassive black hole.

Now, they may have found their answer. The scientists examined a galaxy called 4C12.50. Located nearly 1.5 billion light-years from Earth, the galaxy is at a stage where its black hole "engine" that produces jets is just turning on. At the ends of both jets, the researchers found clumps of hydrogen gas moving outward from the galaxy at 1,000 kilometers per second. One of the clouds had as much as 16,000 times the mass of the sun. The other contained 140,000 times the mass of the sun. In fact, the larger cloud is roughly 160 by 190 light-years in size.

In order to spy this galaxy, the researchers employed a network of worldwide radio telescopes. This allowed them to see the jets like never before. In fact, the scientists discovered that the jets from the galaxy's core can stretch and deform clouds of interstellar gas to expand their "pushing" effect beyond the narrow width of the jets themselves. In addition, they reported that at this particular galaxy's stage of development the jets may turn on and off--and so periodically repeat the process of removing gas from the galaxy.

"This is the most definitive evidence yet for an interaction between the swift-moving jet of such a galaxy and a dense interstellar cloud," said Raffaella Morganti, one of the researchers, in a news release. "We believe we are seeing in action the process by which an active, central engine can remove gas-the raw material for star formation-from a young galaxy."

The findings reveal a little bit more about galaxy formation and show how young galaxies regulate their growth. The latest discovery could show exactly why galaxies don't grow to be so massive.

The findings are published in the journal Science.