This new observation helps astronomers to understand the structure and formation of these massive inhabitants of the centers of galaxies, and the twin high-speed jets of plasma they frequently eject from their poles.
Up to now, only weak magnetic fields far from black holes had been probed. In this study they detected signals directly related to a strong magnetic field very close to the event horizon of the supermassive black hole in a distant galaxy named PKS 1830-211. This magnetic field is located precisely at the place where matter is suddenly boosted away from the black hole in the form of a jet.
The discovery is a giant leap in terms of observing frequency, thanks to the use of ALMA, and in terms of distance to the black hole where the magnetic field has been probed. These results will help us understand what is really going on in the immediate vicinity of supermassive black holes.