A magnetic field in the center of our galaxy could prevent a supermassive black hole.
Supermassive black holes exist in the center of most galaxies, and our Milky Way is no exception.
But many other galaxies have very active black holes, which means that many materials fall there, emitting high energy radiation in this "feeding" process.
In comparison, the central black hole of the Milky Way, called Sagittarius A *, is relatively calm.
NASA scientists believe that this is due to the strong magnetic field in the center of the Milky Way, which is powerful enough to limit turbulent gas movements.
"If the magnetic field channels the gas so that it gets into the black hole itself, the black hole is active because it consumes a lot of gas," says NASA.
"However, if the magnetic field channels the gas to orbit the black hole, it is silent because it does not ingest any gas that would otherwise form new stars."
NASA scientists used a new high resolution instrument called HAWC + (Airborne Wideband Camera Plus) to visualize this magnetic field for the first time.
Magnetic fields being invisible forces, they can not be directly visualized, but the HAWC + instrument detects polarized infrared light emitted by celestial dust particles. These grains align perpendicular to the magnetic fields.
From the results, astronomers can map the shape and deduce the force of the otherwise invisible magnetic field, thus helping to visualize this fundamental force of nature.
"The spiral shape of the magnetic field channels the gas into an orbit around the black hole," said Darren Dowell, scientist at NASA's Jet Propulsion Laboratory, principal investigator of the HAWC + instrument and lead author of the 39; study.
"This could explain why our black hole is silent while others are active.