Perturbation structures in magnetized relativistic winds

A perturbation formulation is presented for steady three-dimensional compressible structures embedded in a background relativistic magnetohydrodynamic (RMHD) radial outflow with spherical symmetry. The property of the two concurred RMHD fast and slow critical points is examined. Explicit perturbation solutions at large radii are derived analytically in a polytropic background wind. This perturbation approach for compressible structures together with our recent analyses on propagation of Alfvénic perturbations in a RMHD wind forms a useful starting basis for modeling a broad class of complex structures in magnetized relativistic astrophysical outflows.