Astronomers using a worldwide network of radio telescopes
have found strong evidence that a powerful jet of material propelled to nearly
light speed by a galaxy's central black hole is blowing massive amounts of gas
out of the galaxy. This process, they said, is limiting the growth of the black
hole and the rate of star formation in the galaxy, and thus is a key to
understanding how galaxies develop.
Astronomers have theorized that many galaxies should be more
massive and have more stars than is actually the case. Scientists proposed two
major mechanisms that would slow or halt the process of mass growth and star
formation -- violent stellar winds from bursts of star formation and pushback
from the jets powered by the galaxy's central, supermassive black hole.