‘Supernova sweeping’ cleans up a galaxy’s gas

After black holes quiet star formation, massive explosions put an end to it

SPRING CLEANING Jets erupting from a supermassive black hole, such as the one in Centaurus A (shown in this color composite image), might clear the way for supernovas to sweep out gas and stop star formation.

WFI/ESO (optical); A. Weiss et al/APEX/MPIfR and ESO (submillimeter); R. Kraft et al/CXC/CfA and NASA (x-ray)

By Christopher Crockett

March 30, 2015 at 7:30 am

Supernova sweeping
SOO-per-NOH-vah SWEEP-eeng n.

A process in which exploding stars push gas out of a galaxy.

Supernovas might be the maid service of the universe. These explosions of stellar remnants work hand in hand with supermassive black holes to sweep out gas and shut down galaxies’ star-forming factories, new research suggests.

The black holes 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, researchers suggest March 10 at arXiv.org. A celestial cleaning partnership might help astronomers understand why some massive galaxies stopped forming stars billions of years ago.