Winds of Change around Black Holes

Accretion disks, where matter with angular momentum spirals down through a disk, occur around objects ranging from the youngest stars to supermassive black holes. But not all of this material reaches the center of the disk. Instead, some material is accelerated away from the disk. These outflows can be ejected in a narrow opening angle (what astronomers call "jets") or can be relatively unfocused (what astronomers call "winds"). While we do not know the precise processes that accelerate and collimate winds and jets, magnetic fields almost certainly play a key role.