ELECTROMAGNETICALLY DRIVEN RELATIVISTIC JETS - A CLASS OF SELF-SIMILAR SOLUTIONS

We have constructed a class of self-similar solutions for relativistic winds driven by rotating magnetic fields. These winds are collimated to cylindrical jet flows of finite radii and may attain supermagnetosonic speeds with high Lorentz factors. Most of the flow acceleration results from the "magnetic nozzle" effect and occurs beyond the fast magnetosonic point, which is typically located a few light cylinder radii from the rotation axis. Approximate equipartition between the electromagnetic and flow kinetic energies is generally achieved for these jets, in contrast to the radial wind case in which the flow is magnetically dominated at all radii.