A composite image of the active galaxy Centaurus A shows huge jets extending millions of light years into space, presumably fired out from a central supermassive black hole. Image: Optical: ESO/WFI; Submillimeter: MPIfR/ESO/APEX/A.Weiss et al.; X-ray: NASA/CXC/CfA/R.Kraft et al.
Lurking in the cores of active galaxies are supermassive black holes that can blast out enormous jets of charged particles stretching millions of light years into space. The processes that generate those jets may be responsible for cosmic rays that carry millions of times the energy produced in the most powerful particle accelerators on Earth.
Exactly what mechanism powers those galactic jets is not known. But a new computer simulation at the SLAC National Accelerator Laboratory in Menlo Park, California, indicates distorted magnetic fields, tangled like spaghetti, create powerful electric fields in the direction of the jets, setting up dense currents of high-energy particles streaming away into space.
Using the Mira supercomputer at the Argonne National Laboratory, the researchers simulated the motions of up to 550 billion particles, mimicking a cosmic jet, and then scaled up the results to compare with actual observations. The simulations showed that when a helical magnetic field, created by a spinning supermassive black hole, is distorted ...