How do Radio Galaxies form?
In the late 1970s, jets were discovered in megaparsec-long radio galaxies. I developed a ‘slender’ hydrodynamical theory for jets. This involved the first quantitative analysis of jet warping, bending and disruption in galactic halos. I established a background of theory to which observed behaviour is compared and contrasted. A full treatment of laminar jets, including the nozzle, gravity and splitting, has since been completed. 2. What are Hot Spots? Hot spots are created where a jet finally crashes into the surrounding medium. I made the first sophisticated numerical simulations of supersonic jets with Michael Norman and Larry Smarr (Illinois)$^7$. Cocoons, oblique shocks and Mach discs were revealed. Synthetic ‘hot spot’ maps were generated which contain many of the observed hot spot features and led to the first classification scheme. 3. How do Jets form? Stellar and extragalactic outflows may be funnelled through de Laval nozzles$^4$, regions which are prone to Rayleigh-Taylor and
