Figure 24-7: Jets from a Supermassive Black Hole The rotation of the accretion disk surrounding a supermassive black hole twists the disk’s magnetic field lines into a helix. The field then channels the flow of subatomic particles pouring out of the disk. Over a distance less than a light-year, this channeling changes a broad flow into a pair of tightly focused jets, one on each side of the disk. Figure 18-16 shows a similar process that takes place on a much smaller scale in protostars.

(NASA and Ann Feild, Space Telescope Science Institute)