How supernovas clean up the universe

Acting as a maid service of the universe, Supernovas have helped clean up galaxies.

It seems these explosions that mark the end of a star's life work hand-in-hand with super massive black holes to sweep out gas and shut down galaxies' star-forming factories.

Recent research, led by Michigan State University astronomers, finds that the black holes located at the cores of galaxies launch fountains of charged particles, which can stir up gas throughout the galaxy and temporarily interrupt star formation.

But unless something intervenes, the gas will eventually cool and start forming stars again.

One mega-outburst from the black hole, though, could heat the gas surrounding the galaxy enough to let supernovas take over and mop up the mess. A celestial cleaning partnership might help astronomers understand why some massive galaxies stopped forming stars billions of years ago.

Team leader and MSU professor Mark Voit said that their previous research had shown that black-hole outbursts could limit star formation in massive galaxies, but they couldn't completely shut it off. Something else was needed to keep sweeping out the gas that dying stars continually dump into a galaxy, and supernova sweeping appears to work perfectly for that.

The research is published in Science News and Astrophysical Journal, Letters.