Radio Galaxies and Jet Dynamics

The numerical and theoretical study of extragalactic radio jets is a closely related area of PEGA research, led by Dr. Wiita. These beams of relativistic plasma are launched from the accretion disks in the vicinity of the SMBHs, and can propagate millions of light years outside the parent galaxies filling huge lobes. Shocks within these jets can produce many of the variations seen in the radio and other bands. Three-dimensional simulations run on national supercomputing facilities have been investigated by PEGA scientists. Current and proposed investigations include: interactions of radio jets with massive clouds; the triggering of extensive star and galaxy formation at high redshifts; and the spreading of magnetic fields and enriched galactic gas into the intergalactic medium.

A supercomputer simulations of supersonic radio jets propagating through massive clouds in galactic atmospheres is shown in the figure. The three images in the figure, on the left side, are snapshots of the densities of a Mach 6 jet calculation, while those on the right are for a Mach 3 jet. For details, see Wang, Wiita and Hooda, Radio Jet Interactions with Massive Clouds, The Astrophysical Journal, 534, 201 (2000).