Polarization of synchrotron emission from relativistic reconfinement
  shocks
  We study the polarization properties of relativistic reconfinement shocks
with chaotic magnetic fields. Using our hydrodynamical model of their
structure, we calculate synthetic polarization maps, longitudinal polarization
profiles and discuss the spatially averaged polarization degree as a function
of jet half-opening angle Theta_j, jet Lorentz factor Gamma_j and observer
inclination angle to the jet axis theta_{obs}. We find, that for theta_{obs} <=
Theta_j the wave electric vectors are parallel in the vicinity of the structure
ends and perpendicular in between, while for theta_{obs} > Theta_j the
polarization can only be perpendicular. The spatially averaged polarization
degree does not exceed 30%. Parallel average polarization, with polarization
degrees lower than 10%, have been found for theta_{obs} < Theta_j under the
condition Gamma_j * Theta_j > 1. As earlier works predicted the parallel
polarization from relativistic conical shocks, we explain our results by
discussing conical shocks with divergent upstream flow.
