Plasma beams from doughnuts

A single model that explains the jets seen in radio galaxies and SS433, in which gas is accelerated by radiation pressure from a doughnut, is proposed. It has long been suspected that the extended lobes of double radio sources are powered by beams of material being ejected from the central galaxy. It is suggested that in cases where the viscosity is small, a doughnut or torus of gas may form in orbit around a compact body (neutron star or black hole) and that this can provide an alternative to accretion disks in explaining the energy requirements of quasars. This model seems to indicate what to expect from gas flows off standard alpha disks. General validity is implied in application to axisymmetric accretion systems.