Scientists have caught one of the best glimpses yet of a jet of plasma streaming from the black hole at the heart of a distant galaxy.

Intense magnetic fields around black holes are thought to launch these beams, which travel nearly at the speed of light, but the beams' exact origins remain unknown.

Bia Boccardi of the Max Planck Institute for Radio Astronomy in Bonn, Germany, and her colleagues used a global array of radio telescopes to image the base of the jet at the core of the galaxy Cygnus A at high resolution. They found that the base is hundreds of times wider than the event horizon of the black hole, extending into the swirling disk of material that surrounds it.

This suggests that the rotation of the disk helps to launch the jet.

Astron. Astrophys. 588, L9 (2016)