60秒科学:Black Hole Quasar Building Galaxy（在线收听）

Black Hole Quasar Building Galaxy
A study in the journal Astronomy & Astrophysics finds that a distant quasar, powered by a black hole, is building a galaxy that will eventually surround the black hole. Cynthia Graber reports

Which came first, black holes or galaxies? It’s been a bit of a conundrum for astrophysicists. Black holes are known to devour matter, but did they arise before or after, the galaxies in which they exist? Now, scientists say it looks like the black holes build their own galaxies. The research was published in the journal Astronomy & Astrophysics.

Scientists were checking out a quasar, an incredibly distant, incredibly bright object. This quasar was the only one without a known host galaxy. Researchers thought the galaxy must be hidden behind some dust. But they didn’t find one. What they did find is a nearby galaxy that’s producing stars at a rapid pace—the equivalent of about 350 suns per year, a hundred times faster than typical galaxies.

Scientists observed that the quasar is shooting out highly energetic particles and fast-moving gas in the direction of the galaxy. It looks as if that’s inducing the creation of those stars. So the galaxy will keep growing until it envelops the quasar itself. The researchers conclude that galaxies may thus be formed by clouds of gas that are bombarded by streams of matter and energy from black holes—which are building their own homes.